It is an all too common scenario in the landscape, but a discerning eye can pick it up and get it right just about every time.
The scenario goes something like this. There are several trees, usually close together, planted just about the same time in just about the same way. Every tree but one is doing just fine. They all have green leaves and are growing well. The one that is doing poorly is stunted and displays yellow leaves that die back far too soon. Sound familiar? Unfortunately in the desert, this is a very common complaint.
Stunted, stressed plants in the midst of neighbors planted at the same time and treated in the same way usually is a dead giveaway that there is a layer of caliche below the surface of the soil. It is a silent, invisible troublemaker that can cause real problems. In most cases, you will never know it is there until the plants start screaming for help.
Caliche is usually a cemented soil layer containing large amounts of calcium carbonate, or lime. It binds sand and gravel together so hard and tight that roots and water have a difficult time getting through. It is light in color and it is difficult to dig through. Anyone who has tried to dig through caliche will never forget the experience. The clincher in identifying caliche is to sprinkle a few drops of vinegar or some other acid onto the surface of the layer. If it is caliche, it will fizz or bubble as soon as the drops hit the caliche.
Caliche does not necessarily have to be in layers. It can also be found in lumps or even granules within the soil. The vinegar test is the best way to tell for sure if it is there. Caliche can be close to the surface of the soil, on top of the soil or far below. It can run anywhere from a few inches to many feet thick. There can even be more than one layer!
Iron chlorosis is one of the common problems of plants in or near caliche. The pH of the soil is high enough to cause iron to become unavailable to the plants. The usual symptoms are yellowing, dark veins, and untimely leaf drop.
A second problem is the lack of water and root penetration. Even if the layer is loose, roots may still not penetrate.
A third problem is drainage. The soil must be allowed to drain to insure adequate levels of oxygen for root growth. A yellowing or type of chlorosis may be seen if the root zone does not have enough oxygen. Overwatering can also cause a similar yellow symptom.
The best way to avoid damage to plants from caliche is to try to keep plant roots out of the caliche zone. Obviously, this is easier said than done. One way to do this is to dig the tree or shrub hole early and test for drainage by filling the hole with water and seeing how long it takes to empty. If the water level drops four inches or more in four hours, caliche is probably not present and the drainage should be all right.
If caliche is present, if possible, remove the caliche and replace it with soil similar to that which is in the area before planting. Do not try to reclaim the caliche with soil amendments. Unless there is just a small amount of caliche present, acid soil amendments, organic matter and other treatments will work so slowly that it may take years to see any difference. Just dig it out and get rid of it.
The planting hole is also important in managing caliche. It should be large enough to accommodate the root system of mature trees and shrubs. This means that the planting hole should be up to five times the diameter of the container in which the new plant comes from the nursery. The hole need not be deep, because most desert-adapted trees and shrubs, like mesquite and Cassia, are relatively shallow rooted under normal landscape conditions. In all cases, however, the hole, or at least a small chimney, must extend down through the caliche layer to avoid drainage and resulting salinity problems.
If it is not possible to dig down through the caliche layer and remove it, then it will be important to avoid it. Choose another location that is free from caliche, or construct a raised bed to elevate the plants above the caliche layer sufficiently high to provide good drainage. Someone I know had to deal with an extremely thick caliche layer that was close to the soil. He solved the problem by purchasing railroad ties and stacking them up to waist high and then filling the new box with planting soil. Into this construction he planted full-sized citrus trees which flourished in a spot where otherwise they would have struggled.
Caliche is very common throughout Pinal County in desert soils. If we can find a way around or through a caliche layer so that salts and excess water can drain through to a more absorbent layer of soil below, in many cases affected plants will quickly recover and catch up with their neighbors.
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85122
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Thursday, June 27, 2013
Wednesday, June 26, 2013
Controlling Weeds and Diseases with Sunlight
Harnessing the energy of the sun may be the best way to control soil-borne plant diseases and some weeds.
Root knot nematodes, verticillium wilt fungi, weed seeds, and other potential problems can lurk in your garden’s soil. Sooner or later, when you least expect them, bam!, there they are. One way to minimize these problems is to heat the soil using the warmth of the sun. The build up of heat within the soil kills enough of them to suppress or even prevent their effects during a growing season.
Called soil solarization, heating the soil with sunlight has been shown to kill weed seeds, plant pathogenic nematodes, and some soil-borne plant diseases. It has also been shown to slow down, but generally not completely kill weedy perennial plants like Bermudagrass and nutsedge. Tested in many countries around the world, the technique has pretty much been shown to work under many different climates and against many different pest problems.
If you want to learn more about soil solarization, a quick web search on line will deliver a wealth of information at a touch of your fingers. My favorite web site for pest control information is the University of California Integrated Pest Management site. Backed by a number of years of field research, it is an excellent reference for desert gardeners and farmers. The specific reference on soil solarization can be found at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74145.html.
Soil solarization works best against plant pathogenic fungi, destructive bacteria, and weed seeds and seedlings. Common examples of diseases controlled include Verticillium wilt, which causes problems in tomatoes and other garden plants; Phytophthora root rot, and crown gall.
Solar solarization does not work all that well with deep-rooted perennial weeds such as Burmudagrass and nutsedge. Underground stems of these weeds need to be within the top eight inches of the soil in order to be affected by solarization. Most deep rooted perennials will have roots much deeper than eight inches, but good suppression of these weedy plants can be achieved with solarization. You will probably get one season after treatment before the weeds return. When they do, solarization can be repeated.
Occasionally, root knot nematodes can be a problem in Pinal County gardens and landscapes. Nematodes are small roundworms, almost microscopic in size, that live in the soil. These are not segmented worms, like the earthworm. They are an entirely separate kind of animal. Some nematodes are beneficial in gardens because they attack insects and other nematodes. The root knot nematodes, however, are plant feeders and can cause lots of problems.
Root knot nematodes cause large, misshapen swellings, called galls, on the roots of susceptible plants. These grotesque, outsized galls slow down the movement of water and nutrients within the plants and can cause the plants to become stunted and unproductive.
Solar solarization, correctly done, can reduce populations of the root knot nematodes and other plant parasitic nematodes within the top six to eight inches of the soil. Unfortunately, because the animals are fairly mobile and somewhat heat resistant, complete control is difficult. Shallow rooted crops, however, planted right after solarization should be okay. Solarization may have to be repeated regularly from year to year to keep root knot nematode populations under control.
Soil solarization is best done with clear plastic sheets laid upon the surface of the soil. It is the sunlight penetrating through the plastic to the soil that heats up the ground underneath the plastic to levels that are lethal to the target pests.
Selection of the proper type of plastic is essential. The thinner plastics transmit heat better than the thicker sheets. However, the thicker the plastic, the better it can withstand wind and other environmental challenges. The thinner plastic films in the one mil range are commonly selected where wind and animal foot prints will not be a problem. In areas that experience more wind, plastic sheets up to two mils or higher may be needed. A mil is measured at 0.001 inch.
The length of time that a plastic sheet must be in place varies with the solar gain and with the time of year. The cooler the temperatures, the longer the plastic will need to be left in place to achieve effective control. During our hot summers, a solarization treatment time of between four and six weeks should be sufficient. In cooler times, or windier areas, it may be necessary to leave the plastic in place up to eight weeks. If left in place much longer than that, the plastic begins to decompose, lose its effectiveness, and break into pieces from ultraviolet (UV) light exposure. When that occurs, cleanup becomes more difficult.
Good soil preparation will be essential in order to achieve satisfactory results. The first step is to determine the area to be treated. In some cases where a garden may have serious infestations of disease or heavy weed seed populations, the entire garden may need to be treated. Where weed seed populations may be lighter, or where disease incidence is variable, smaller areas where there are known problems can be treated separately.
The surface of the soil must be perfectly flat and clear of rocks, soil clods, and dead plant material in order to get the best results from solarization. The shorter the distance between the plastic and the surface of the soil, the better the transmission of the sun’s radiant heat. The better the heat transmission, the deeper the heat will penetrate into the soil.
It will also be important to saturate the soil with water before laying the plastic down. Water increases the susceptibility of the target pests to heat, and also helps heat up the soil profile. A good, deep irrigation before applying the plastic is essential.
Some people have achieved better results by irrigating the soil once or twice after the plastic has been laid down. They install drip irrigation tubes or soaker hoses prior to laying the plastic. Occasional irrigations allow them to maintain soil saturation.
In order to maintain good plastic to soil contact, to prevent premature drying of the soil, and to prevent wind damage, it will be important to seal the edges of the plastic with soil. A recommended procedure is to dig a five to eight inch trench around the circumference of the plastic. The plastic is then carefully stretched over the area to be treated with the edges of the plastic laying in the bottom of the trench. The trench is then filled with soil and the plastic is secured.
Soil solarization is best done during the summer months. Certainly the greatest soil temperatures will be recorded during then. However, solarization can also be done at other times during the year, including the winter months, but it is generally understood that the plastic must be left in place for a longer time, and that the depth of heating into the soil may be less. During the cooler months, black plastic instead of the normal clear plastic may be a better choice because it will absorb more heat on a chilly day.
While not perfect, soil solarization can help control weed and disease problems in local gardens and landscapes with a minimum of work and without using chemical pesticides.
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85122
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Root knot nematodes, verticillium wilt fungi, weed seeds, and other potential problems can lurk in your garden’s soil. Sooner or later, when you least expect them, bam!, there they are. One way to minimize these problems is to heat the soil using the warmth of the sun. The build up of heat within the soil kills enough of them to suppress or even prevent their effects during a growing season.
Called soil solarization, heating the soil with sunlight has been shown to kill weed seeds, plant pathogenic nematodes, and some soil-borne plant diseases. It has also been shown to slow down, but generally not completely kill weedy perennial plants like Bermudagrass and nutsedge. Tested in many countries around the world, the technique has pretty much been shown to work under many different climates and against many different pest problems.
If you want to learn more about soil solarization, a quick web search on line will deliver a wealth of information at a touch of your fingers. My favorite web site for pest control information is the University of California Integrated Pest Management site. Backed by a number of years of field research, it is an excellent reference for desert gardeners and farmers. The specific reference on soil solarization can be found at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74145.html.
Soil solarization works best against plant pathogenic fungi, destructive bacteria, and weed seeds and seedlings. Common examples of diseases controlled include Verticillium wilt, which causes problems in tomatoes and other garden plants; Phytophthora root rot, and crown gall.
Solar solarization does not work all that well with deep-rooted perennial weeds such as Burmudagrass and nutsedge. Underground stems of these weeds need to be within the top eight inches of the soil in order to be affected by solarization. Most deep rooted perennials will have roots much deeper than eight inches, but good suppression of these weedy plants can be achieved with solarization. You will probably get one season after treatment before the weeds return. When they do, solarization can be repeated.
Occasionally, root knot nematodes can be a problem in Pinal County gardens and landscapes. Nematodes are small roundworms, almost microscopic in size, that live in the soil. These are not segmented worms, like the earthworm. They are an entirely separate kind of animal. Some nematodes are beneficial in gardens because they attack insects and other nematodes. The root knot nematodes, however, are plant feeders and can cause lots of problems.
Root knot nematodes cause large, misshapen swellings, called galls, on the roots of susceptible plants. These grotesque, outsized galls slow down the movement of water and nutrients within the plants and can cause the plants to become stunted and unproductive.
Solar solarization, correctly done, can reduce populations of the root knot nematodes and other plant parasitic nematodes within the top six to eight inches of the soil. Unfortunately, because the animals are fairly mobile and somewhat heat resistant, complete control is difficult. Shallow rooted crops, however, planted right after solarization should be okay. Solarization may have to be repeated regularly from year to year to keep root knot nematode populations under control.
Soil solarization is best done with clear plastic sheets laid upon the surface of the soil. It is the sunlight penetrating through the plastic to the soil that heats up the ground underneath the plastic to levels that are lethal to the target pests.
Selection of the proper type of plastic is essential. The thinner plastics transmit heat better than the thicker sheets. However, the thicker the plastic, the better it can withstand wind and other environmental challenges. The thinner plastic films in the one mil range are commonly selected where wind and animal foot prints will not be a problem. In areas that experience more wind, plastic sheets up to two mils or higher may be needed. A mil is measured at 0.001 inch.
The length of time that a plastic sheet must be in place varies with the solar gain and with the time of year. The cooler the temperatures, the longer the plastic will need to be left in place to achieve effective control. During our hot summers, a solarization treatment time of between four and six weeks should be sufficient. In cooler times, or windier areas, it may be necessary to leave the plastic in place up to eight weeks. If left in place much longer than that, the plastic begins to decompose, lose its effectiveness, and break into pieces from ultraviolet (UV) light exposure. When that occurs, cleanup becomes more difficult.
Good soil preparation will be essential in order to achieve satisfactory results. The first step is to determine the area to be treated. In some cases where a garden may have serious infestations of disease or heavy weed seed populations, the entire garden may need to be treated. Where weed seed populations may be lighter, or where disease incidence is variable, smaller areas where there are known problems can be treated separately.
The surface of the soil must be perfectly flat and clear of rocks, soil clods, and dead plant material in order to get the best results from solarization. The shorter the distance between the plastic and the surface of the soil, the better the transmission of the sun’s radiant heat. The better the heat transmission, the deeper the heat will penetrate into the soil.
It will also be important to saturate the soil with water before laying the plastic down. Water increases the susceptibility of the target pests to heat, and also helps heat up the soil profile. A good, deep irrigation before applying the plastic is essential.
Some people have achieved better results by irrigating the soil once or twice after the plastic has been laid down. They install drip irrigation tubes or soaker hoses prior to laying the plastic. Occasional irrigations allow them to maintain soil saturation.
In order to maintain good plastic to soil contact, to prevent premature drying of the soil, and to prevent wind damage, it will be important to seal the edges of the plastic with soil. A recommended procedure is to dig a five to eight inch trench around the circumference of the plastic. The plastic is then carefully stretched over the area to be treated with the edges of the plastic laying in the bottom of the trench. The trench is then filled with soil and the plastic is secured.
Soil solarization is best done during the summer months. Certainly the greatest soil temperatures will be recorded during then. However, solarization can also be done at other times during the year, including the winter months, but it is generally understood that the plastic must be left in place for a longer time, and that the depth of heating into the soil may be less. During the cooler months, black plastic instead of the normal clear plastic may be a better choice because it will absorb more heat on a chilly day.
While not perfect, soil solarization can help control weed and disease problems in local gardens and landscapes with a minimum of work and without using chemical pesticides.
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85122
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Tuesday, June 25, 2013
Useful Weed Control Tools
In most gardens and landscapes, weeds can be a real problem.
Weedy plants are aggressive, fast-growing species that crowd out desirable plants by stealing space, sunlight, water and nutrients. Unless these pests are controlled in a timely manner, they can seriously affect the growth and development of garden and landscape plants. Here are a few tools that I find useful when combating weeds in my yard.
Mechanical weed control techniques have been around for as long as humans have encouraged the growth of useful plants. Removing weeds by pulling or hoeing is not always fun nor easy, but, when the weeds get out of hand, sometimes pulling, hoeing or cutting are the only effective ways to solve the problem. Fortunately, there are a number of useful tools that can make mechanical weed control easier.
A small pocket knife, such as what might be carried in a pocket or purse, is just the right size to cut small weeds that grow from cracks and crevasses in concrete walks, driveways and tennis courts. A thin knife blade can easily be inserted deep into a crack to cut the weed below the crown, the spot where the stem and the taproot join. It is important to cut below the crown because many weedy plants have dormant buds in that area. If the crown is not removed, the plant will grow back again from those buds.
Another useful tool is the linoleum knife. It has a stout blade with a hook on the end and a wooden or plastic handle that allows a good hand grip. The linoleum knife is excellent for removing weeds that are in close proximity to bedding or garden plants. A large hoe or shovel might be easier to use, but they are so unwieldy in tight places that it is almost impossible to get all of the weeds without doing damage to the desirable plants. A medium-sized, single-bladed knife can be worked in alongside plants to cut the roots of weeds without disturbing those plants that we wish to protect.
When working with these knives, it is important to wear heavy gloves because as the work speeds up and the off hand is used to hold the weed for cutting, sometimes the knife blade can get a little too close to fingers or hands. Good safety protection is important. Since working close to bedding plants often requires kneeling on the ground, a set of knee pads can be a good investment.
Another useful tool is a small, multi-tined cultivation fork. These tools resemble claws and usually have three to four tines attached to a handle. The value of these tools is twofold. First, they loosen and aerate the soil by breaking up surface crusts. Second, the movement of the tines through the soil damages or removes small weed seedlings. This tool generally is less successful for weed control when the weeds have more than two or three leaves.
The push-pull hoe is a tool that does its work, not with a chopping motion, but with a back and forth motion as it is pulled and pushed through the soil. The push-pull hoe slices through weed roots just below the surface of the soil and generally requires less force to operate than the standard chopping hoe. The push-hull hoe is a good tool to safely work around above ground drip lines because it slips along side and just underneath the drip tubing without danger of nicking or cutting the plastic tubes. Tools which require a chopping action are difficult to control. Lack of tool control generally leads to mistakes.
The narrow-bladed chopping hoe is a variation on a standard chopping hoe. While the larger hoe works well in wide open spaces, the narrow hoe is much easier to use where plants are placed close together. The narrow hoe will have a blade anywhere from one to two inches in width. However, even a narrow hoe seems magnetically attracted to plastic drip irrigation tubes.
Garden tillers can make quick work of small weeds in between rows of vegetables or flowers. A light weight tiller is best for this type of work because it is generally smaller and easier to control. In heavy soils, or in gardens where the spacing is larger, a heavy duty model may be a better choice. If possible, space the garden rows far enough apart to allow the tiller to pass safely between the rows without damaging the plants.
A flat blade attached to a handle by a hoop is called a weed hook This tool works with a swinging motion and, if handled correctly, can slice weeds off close to the surface of the soil. It is quite effective for clearing large patches of weeds in wide open spaces. The blade must be kept sharp with a file in order to work at peak performance.
When using a weed hook, it is important to make sure that the work area is kept clear of pets and people. The swinging motion of the hook can cause serious injury to those unaware of the danger. A new operator may find that it is difficult to keep the blade out of the dirt and away from rocks as it is swung back and forth. Practice will soon provide experience to correctly judge the correct height to swing the blade.
String trimmers, which are normally used to edge lawns, are also good weed control tools for alleys and other open spaces. A low horsepower, thin-lined model will work good for small weeds, but once the weeds mature, a larger machine with heavy line will be needed to cut through their tough stems. Because the whirling string can kick up small rocks and sand, it is important to wear eye protection.
When using string trimmers to cut grass and weeds around the trunks of trees and shrubs, remember that the string can easily damage the tender bark of many plants. Girdling a trunk or stem can cause enough damage to kill the plant. Always place a shield around the trunks of these plants before approaching with the string trimmer.
The standard lawn mower also makes a good weed control tool. Heavy duty and rugged, a lawn mower can easily cut through most weeds. If it is equipped with a catch basket, it can save a step in the clean up process by taking away the need to rake up the weeds after cutting. The power mower is excellent for a quick alley cleanup, but it is important to make sure that all rocks are removed before mowing so that damage to the mower blade and injury to pets, children and innocent bystanders does not occur.
Weed control can be a challenge in any type of garden or landscape, even low maintenance desert landscapes, but a few tools can make mechanical removal of weeds more effective and easy.
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85222
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Weedy plants are aggressive, fast-growing species that crowd out desirable plants by stealing space, sunlight, water and nutrients. Unless these pests are controlled in a timely manner, they can seriously affect the growth and development of garden and landscape plants. Here are a few tools that I find useful when combating weeds in my yard.
Mechanical weed control techniques have been around for as long as humans have encouraged the growth of useful plants. Removing weeds by pulling or hoeing is not always fun nor easy, but, when the weeds get out of hand, sometimes pulling, hoeing or cutting are the only effective ways to solve the problem. Fortunately, there are a number of useful tools that can make mechanical weed control easier.
A small pocket knife, such as what might be carried in a pocket or purse, is just the right size to cut small weeds that grow from cracks and crevasses in concrete walks, driveways and tennis courts. A thin knife blade can easily be inserted deep into a crack to cut the weed below the crown, the spot where the stem and the taproot join. It is important to cut below the crown because many weedy plants have dormant buds in that area. If the crown is not removed, the plant will grow back again from those buds.
Another useful tool is the linoleum knife. It has a stout blade with a hook on the end and a wooden or plastic handle that allows a good hand grip. The linoleum knife is excellent for removing weeds that are in close proximity to bedding or garden plants. A large hoe or shovel might be easier to use, but they are so unwieldy in tight places that it is almost impossible to get all of the weeds without doing damage to the desirable plants. A medium-sized, single-bladed knife can be worked in alongside plants to cut the roots of weeds without disturbing those plants that we wish to protect.
When working with these knives, it is important to wear heavy gloves because as the work speeds up and the off hand is used to hold the weed for cutting, sometimes the knife blade can get a little too close to fingers or hands. Good safety protection is important. Since working close to bedding plants often requires kneeling on the ground, a set of knee pads can be a good investment.
Another useful tool is a small, multi-tined cultivation fork. These tools resemble claws and usually have three to four tines attached to a handle. The value of these tools is twofold. First, they loosen and aerate the soil by breaking up surface crusts. Second, the movement of the tines through the soil damages or removes small weed seedlings. This tool generally is less successful for weed control when the weeds have more than two or three leaves.
The push-pull hoe is a tool that does its work, not with a chopping motion, but with a back and forth motion as it is pulled and pushed through the soil. The push-pull hoe slices through weed roots just below the surface of the soil and generally requires less force to operate than the standard chopping hoe. The push-hull hoe is a good tool to safely work around above ground drip lines because it slips along side and just underneath the drip tubing without danger of nicking or cutting the plastic tubes. Tools which require a chopping action are difficult to control. Lack of tool control generally leads to mistakes.
The narrow-bladed chopping hoe is a variation on a standard chopping hoe. While the larger hoe works well in wide open spaces, the narrow hoe is much easier to use where plants are placed close together. The narrow hoe will have a blade anywhere from one to two inches in width. However, even a narrow hoe seems magnetically attracted to plastic drip irrigation tubes.
Garden tillers can make quick work of small weeds in between rows of vegetables or flowers. A light weight tiller is best for this type of work because it is generally smaller and easier to control. In heavy soils, or in gardens where the spacing is larger, a heavy duty model may be a better choice. If possible, space the garden rows far enough apart to allow the tiller to pass safely between the rows without damaging the plants.
A flat blade attached to a handle by a hoop is called a weed hook This tool works with a swinging motion and, if handled correctly, can slice weeds off close to the surface of the soil. It is quite effective for clearing large patches of weeds in wide open spaces. The blade must be kept sharp with a file in order to work at peak performance.
When using a weed hook, it is important to make sure that the work area is kept clear of pets and people. The swinging motion of the hook can cause serious injury to those unaware of the danger. A new operator may find that it is difficult to keep the blade out of the dirt and away from rocks as it is swung back and forth. Practice will soon provide experience to correctly judge the correct height to swing the blade.
String trimmers, which are normally used to edge lawns, are also good weed control tools for alleys and other open spaces. A low horsepower, thin-lined model will work good for small weeds, but once the weeds mature, a larger machine with heavy line will be needed to cut through their tough stems. Because the whirling string can kick up small rocks and sand, it is important to wear eye protection.
When using string trimmers to cut grass and weeds around the trunks of trees and shrubs, remember that the string can easily damage the tender bark of many plants. Girdling a trunk or stem can cause enough damage to kill the plant. Always place a shield around the trunks of these plants before approaching with the string trimmer.
The standard lawn mower also makes a good weed control tool. Heavy duty and rugged, a lawn mower can easily cut through most weeds. If it is equipped with a catch basket, it can save a step in the clean up process by taking away the need to rake up the weeds after cutting. The power mower is excellent for a quick alley cleanup, but it is important to make sure that all rocks are removed before mowing so that damage to the mower blade and injury to pets, children and innocent bystanders does not occur.
Weed control can be a challenge in any type of garden or landscape, even low maintenance desert landscapes, but a few tools can make mechanical removal of weeds more effective and easy.
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85222
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Friday, June 21, 2013
Small Patio Gardens Can Provide Vegetables and Flowers Year ‘Round
Because of limited space, time or resources, a large vegetable or flower garden for many may simply be too much. For those who fall in this category, but crave the taste of a vine-ripe tomato or the smell of fresh cut flowers on the dining room table, the Square Foot Garden system may just be the answer.
Some years ago, Mel Bartholomew made Square Foot Gardening popular when he published a book by that name and today many find that his system is just right for their needs.
Gardening by the square foot requires that available space be divided up into 12 inch by 12 inch squares each separated by some type of wood or concrete barrier. Each square becomes, in itself, an individual garden, and can be managed independently of all the other squares, if necessary.
Each square usually receives just one plant, especially if that one plant will reach a large size at maturity. The 144 square inches of space are enough to support the roots of one large plant but not more. Some plants that do not have a large, spreading root system, such as carrots, baby lettuce, or some flowers may planted to a higher density. However, the higher the plant density, the more intense the management must be in order to guarantee success.
Gardening by the square foot requires good management consistently applied throughout the growing season. Because of the much smaller area, there will be fewer plants to produce the food or flowers needed for the home and, thus, there is a much smaller allowance for error.
In a large garden, the loss of one or two plants usually is hardly noticed, but in a square foot garden, the loss of even just one plant can be catastrophic. The gardener much be careful that water, nutrients, and pest control strategies are applied at the right time and in the correct amounts to ensure that the garden produces satisfactorily.
The square foot garden works because it allows the gardener to focus attention to individual plants as necessary. Because of this, most plants will be healthier and consequently more productive that those lost in the crowd of a larger garden.
If the small area garden is correctly designed, and with good management, it is quite possible to have a year round garden producing many of the fruits, flowers and vegetables that are so much enjoyed by many people.
First, it is important to design the beds so that they can be easily worked from the edges without having to step into the garden proper to reach the plants. A long, narrow bed, no more than 4 feet wide, but as long as necessary to give the volume of food and flowers needed by the gardener is a common arrangement.
Second, a simple and reliable watering system is essential. Many use a drip or soaker irrigation system attached to a timer to take away the risk of forgetting an irrigation. In summer heat, this could be a fatal omission.
Third, plan ahead for weed and insect control. For most weeds and large insects, like caterpillars, hand picking may be the easiest way to eliminate these pests. For invasive, perennial weeds like nutsedge and bermudagrass, and for tiny insects like whiteflies, aphids and mealy bugs, be prepared to use some other form of pest control appropriate for that specific pest.
Redwood 2 X 4 lumber makes good borders for the square foot garden because of redwood’s pleasing color and resistance to rot. It is a little more expensive, but it will last longer than other types of wood.
Select garden varieties that are specifically adapted to local conditions. With intensive management, it is possible to nurture along some varieties that otherwise would not usually do well in this environment, but for best results, use the tried and tested varieties.
Finally, consider adding hoops to the garden to support clear plastic coverings during the winter and sun screens during the summer to extend growing seasons and improve produce quality.
Supporting hoops can easily be installed using 1 inch PVC plastic pipe. Drill 1 inch holes into the tops of the 2 X 4's almost all the way through the wood every 2 feet using a 1 inch hole saw attached to a power drill. It will be into these holes that the PVC ends will be inserted. For a 4 feet wide bed, use 10 feet long pipe for best results. Some gardeners have used metal stakes driven into the ground instead of drilling the holes. The PVC pipe is fitted over the stakes to keep them in place.
Stabilize the tops of each of the individual hoops by cutting holes into another 2 X 4 at the same distances as were cut into the bed frames. Get someone to help as each individual hoop is threaded through its respective hole. Once the ridge pole is in place, the ends of the pipe can be inserted into the bed frame holes or fitted over the metal stakes.
With the center 2 X 4 now at the peak of the hoops, it will act as a spacer to keep each hoop at the appropriate distance from its neighbor. Stabilize the entire top by staking down the hoop assembly with guy wires or with wood braces at the ends of the bed. Screws inserted through the sides of the garden bed frames into the PVC pipe ends will keep them from working their way out.
Clear plastic during the winter time will keep beds warmer during the cool weather period. If freezing is a risk on cold nights, drape a quilt or sheet over the frames until the sun comes up the next day. If it becomes too hot inside the beds, cut slits through the plastic to let the hot air out. Since the plastic will probably not last more than one season, this is not too much of a loss.
Summer heat and high sunlight intensities can be minimized by spreading shade cloth over the hoops during the summer months. It will keep the garden plants a little cooler and protect tender fruit from sunburning.
By modifying the climate just slightly during the growing season, it is possible to have tomatoes year round and improve the quality of most other plants in season.
For those who are ready to get started in square foot gardening, search the bookstores or the library for a copy of Square Foot Gardening by Mel Bartholomew and let him give you the benefit of his experience
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85122
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Some years ago, Mel Bartholomew made Square Foot Gardening popular when he published a book by that name and today many find that his system is just right for their needs.
Gardening by the square foot requires that available space be divided up into 12 inch by 12 inch squares each separated by some type of wood or concrete barrier. Each square becomes, in itself, an individual garden, and can be managed independently of all the other squares, if necessary.
Each square usually receives just one plant, especially if that one plant will reach a large size at maturity. The 144 square inches of space are enough to support the roots of one large plant but not more. Some plants that do not have a large, spreading root system, such as carrots, baby lettuce, or some flowers may planted to a higher density. However, the higher the plant density, the more intense the management must be in order to guarantee success.
Gardening by the square foot requires good management consistently applied throughout the growing season. Because of the much smaller area, there will be fewer plants to produce the food or flowers needed for the home and, thus, there is a much smaller allowance for error.
In a large garden, the loss of one or two plants usually is hardly noticed, but in a square foot garden, the loss of even just one plant can be catastrophic. The gardener much be careful that water, nutrients, and pest control strategies are applied at the right time and in the correct amounts to ensure that the garden produces satisfactorily.
The square foot garden works because it allows the gardener to focus attention to individual plants as necessary. Because of this, most plants will be healthier and consequently more productive that those lost in the crowd of a larger garden.
If the small area garden is correctly designed, and with good management, it is quite possible to have a year round garden producing many of the fruits, flowers and vegetables that are so much enjoyed by many people.
First, it is important to design the beds so that they can be easily worked from the edges without having to step into the garden proper to reach the plants. A long, narrow bed, no more than 4 feet wide, but as long as necessary to give the volume of food and flowers needed by the gardener is a common arrangement.
Second, a simple and reliable watering system is essential. Many use a drip or soaker irrigation system attached to a timer to take away the risk of forgetting an irrigation. In summer heat, this could be a fatal omission.
Third, plan ahead for weed and insect control. For most weeds and large insects, like caterpillars, hand picking may be the easiest way to eliminate these pests. For invasive, perennial weeds like nutsedge and bermudagrass, and for tiny insects like whiteflies, aphids and mealy bugs, be prepared to use some other form of pest control appropriate for that specific pest.
Redwood 2 X 4 lumber makes good borders for the square foot garden because of redwood’s pleasing color and resistance to rot. It is a little more expensive, but it will last longer than other types of wood.
Select garden varieties that are specifically adapted to local conditions. With intensive management, it is possible to nurture along some varieties that otherwise would not usually do well in this environment, but for best results, use the tried and tested varieties.
Finally, consider adding hoops to the garden to support clear plastic coverings during the winter and sun screens during the summer to extend growing seasons and improve produce quality.
Supporting hoops can easily be installed using 1 inch PVC plastic pipe. Drill 1 inch holes into the tops of the 2 X 4's almost all the way through the wood every 2 feet using a 1 inch hole saw attached to a power drill. It will be into these holes that the PVC ends will be inserted. For a 4 feet wide bed, use 10 feet long pipe for best results. Some gardeners have used metal stakes driven into the ground instead of drilling the holes. The PVC pipe is fitted over the stakes to keep them in place.
Stabilize the tops of each of the individual hoops by cutting holes into another 2 X 4 at the same distances as were cut into the bed frames. Get someone to help as each individual hoop is threaded through its respective hole. Once the ridge pole is in place, the ends of the pipe can be inserted into the bed frame holes or fitted over the metal stakes.
With the center 2 X 4 now at the peak of the hoops, it will act as a spacer to keep each hoop at the appropriate distance from its neighbor. Stabilize the entire top by staking down the hoop assembly with guy wires or with wood braces at the ends of the bed. Screws inserted through the sides of the garden bed frames into the PVC pipe ends will keep them from working their way out.
Clear plastic during the winter time will keep beds warmer during the cool weather period. If freezing is a risk on cold nights, drape a quilt or sheet over the frames until the sun comes up the next day. If it becomes too hot inside the beds, cut slits through the plastic to let the hot air out. Since the plastic will probably not last more than one season, this is not too much of a loss.
Summer heat and high sunlight intensities can be minimized by spreading shade cloth over the hoops during the summer months. It will keep the garden plants a little cooler and protect tender fruit from sunburning.
By modifying the climate just slightly during the growing season, it is possible to have tomatoes year round and improve the quality of most other plants in season.
For those who are ready to get started in square foot gardening, search the bookstores or the library for a copy of Square Foot Gardening by Mel Bartholomew and let him give you the benefit of his experience
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85122
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Thursday, June 20, 2013
Consider Adding a Pomegranate to Your Home Orchard
The bright flowers and zingy taste of the pomegranate make it an ideal fruit tree for desert gardens.
Introduced into California by Spanish missionaries over two hundred years ago, pomegranate has long been a favorite in Arizona for its hardiness, color and fruit. Pomegranates work well in desert landscapes because they are not finicky when it comes to soils and climate.
Native of the Middle East, from Iran to the Himalayan Mountains, pomegranates thrive in semi-arid, mild-temperate to subtropical climates throughout the world. They are naturally adapted to regions with cool winters and hot summers. Pomegranates will live for many years. There are specimens in Europe that are known to be over two hundred years of age.
High humidity seems to adversely affect fruit formation. Because of this, our arid, usually low humidity climate is perfect for the pomegranate. The tree can be severely injured by temperatures below 12° F.
Properly cared for, pomegranate trees can reach heights of fifteen to twenty feet and as many feet wide, but most trees in the desert, for one reason or another, rarely exceed ten feet in height and width. Dwarf varieties are available to fit smaller areas.
The pomegranate is usually deciduous, but the leaves will remain on the tree year round in warmer areas. The trunk is covered by a red-brown bark changing to gray as the tree gets older. You can also tell a pomegranate tree by looking at the leaves. The glossy, leathery leaves are narrow and shaped like a lance tip. There is a strong tendency for the plant to send out sucker shoots from the base of the plant. These should always be kept pruned off.
Attractive scarlet, white, or multi-colored flowers lead to nearly round, two and one-half to five inch-wide fruit. The pomegranate is self fruitful, meaning that it does not need another tree for pollination, and the flowers will accept pollen from themselves or from other flowers brought to them by insects. Cross-pollination increases the fruit set. Wind does not play an important role in pomegranate pollination.
The fruit is surrounded by a tough, leathery skin or rind which is typically yellow inside and light or deep pink or rich red outside. The interior of the fruit is separated by white, spongy, bitter tissue into compartments packed with sacs filled with sweetly acid, juicy, red, pink or whitish pulp. In each sac there is one angular seed. High summer temperatures are essential during the fruiting period to get the best flavor.
The fruit of the ‘Wonderful’ variety, the variety most often planted in Arizona, matures and is ready for harvest in the fall, usually in November, although some other varieties may mature sooner. The fruits are ripe when they have developed a distinctive color and make a metallic sound when tapped. If you are in doubt of the ripeness of the fruit, pick one and test it before harvesting the rest of the fruit from the tree.
Once off the tree, the pomegranate can be stored at a temperature of 32°to 41°F. Some have been able to keep the fruit in storage for up to seven months within this temperature range and at 80 to 85% relative humidity without shrinking or spoiling. The fruits improve in storage, becoming juicier and more flavorful so don’t be in a hurry to use them up. Be sure and save some for later.
The fruit can be eaten right off the tree by deeply scoring the shell several times vertically and then breaking it apart. The clusters of juice sacs are then lifted out from the rind and eaten. The sacs also make an attractive garnish when sprinkled on various dishes.
Pomegranate fruits are often used for juice. After removing the sacs, run them through a basket press or by reaming the halved fruits on an ordinary orange juice squeezer. Another option begins with warming the fruit slightly and rolling it between the hands to soften the interior. A hole is then cut in the stem end and the fruit is placed on a glass to capture the juice as it runs out. Squeeze the fruit from time to time to get all the juice. The juice can be used as a fresh juice, to make jellies, sorbets or cold or hot sauces, and to flavor cakes, baked apples, and other specialties. Pomegranate syrup is sold commercially as grenadine. Pomegranate has been found to be relatively high in antioxidants, compounds that help protect the body from disease.
The pomegranate does best in well-drained ordinary soil, but also thrives in saline soils or even rock strewn gravel. In Arizona, the trees should be lightly fertilized with two to four ounces of ammonium sulfate or other nitrogen fertilizer once during each of the first two springs after planting. At maturity, the tree will do well with three applications of nitrogen fertilizer spread out over the growing season. Fertilize it the same as you would a citrus tree. The trees also respond to an annual mulch of rotted manure or compost.
Once established, pomegranates will take considerable drought, but for good fruit production they must be irrigated regularly. Inconsistent irrigations will cause the fruit rind to split open and allow the entry of insects and diseases. The optimal watering cycle for pomegranates is once a month in the cooler time of year. Once daytime temperatures are consistently above 85 degrees Fahrenheit, then the trees need to be irrigated every 10 to14 days. A good deep watering needs to wet the soil at a depth of two to three feet.
Trees planted during the hot months should be watered every day for the first two weeks to encourage root growth. Afterwards, particularly after new leaf growth begins, the irrigation cycle can gradually be cut back to the normal rotation.
New plants should be pruned back when they are about two feet high. From this point you should allow four or five shoots to develop, but make sure that they are evenly distributed around the stem to keep the plant well balanced. These shoots will develop into scaffold branches that will bear the fruiting wood. Scaffold branches should never be lower than one foot above the ground. Any shoots or branches below this should be considered suckers and removed.
As new branches develop from off the main scaffold branches, make sure to shorten them during January or February each year for the first three years to encourage the maximum number of new shoots on all sides, prevent straggly development, and achieve a strong well framed plant. After the third year, only suckers and dead branches are removed. Since the fruits are borne only at the tips of new growth these extra branches will increase the fruit yield.
The pomegranate can be raised from seed but the plant that results may not have the same characteristics of its parent. For that reason, most new plants are made from cuttings. Pomegranate cuttings root easily and plants from them bear fruit after about three years.
To take cuttings, cut sections of mature, one-year old wood twelve to twenty inches long and remove all of the leaves. Treat the bottom end of the cuttings with rooting hormone and insert about two-thirds their length into the soil or into some other warm rooting medium. Plants can also be air-layered but grafting is seldom successful. Keep the medium well watered and warm and soon roots will form. These cuttings can then be transplanted into place.
When transplanting a pomegranate tree, choose a location with full sun with soil that drains well. The optimal times to transplant trees are in March or October.
Pomegranates are relatively free of most pests and diseases. Minor problems are leaf and fruit spot and foliar damage by white flies, thrips, mealybugs and scale insects, but the roots are seldom bothered by gophers.
Pomegranates can be planted close together for windbreaks, hedges and screens or planted by itself to make a highly decorative accent plant in the landscape. Pomegranates should be placed in the sunniest, warmest part of the yard or orchard for the best fruit, although they will grow and flower in part shade.
The unique taste of the pomegranate fruit, along with its hardiness and attractive flowers, make this plant a good choice for any desert landscape.
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85122
Voice: (520) 836-5221, 227
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Introduced into California by Spanish missionaries over two hundred years ago, pomegranate has long been a favorite in Arizona for its hardiness, color and fruit. Pomegranates work well in desert landscapes because they are not finicky when it comes to soils and climate.
Native of the Middle East, from Iran to the Himalayan Mountains, pomegranates thrive in semi-arid, mild-temperate to subtropical climates throughout the world. They are naturally adapted to regions with cool winters and hot summers. Pomegranates will live for many years. There are specimens in Europe that are known to be over two hundred years of age.
High humidity seems to adversely affect fruit formation. Because of this, our arid, usually low humidity climate is perfect for the pomegranate. The tree can be severely injured by temperatures below 12° F.
Properly cared for, pomegranate trees can reach heights of fifteen to twenty feet and as many feet wide, but most trees in the desert, for one reason or another, rarely exceed ten feet in height and width. Dwarf varieties are available to fit smaller areas.
The pomegranate is usually deciduous, but the leaves will remain on the tree year round in warmer areas. The trunk is covered by a red-brown bark changing to gray as the tree gets older. You can also tell a pomegranate tree by looking at the leaves. The glossy, leathery leaves are narrow and shaped like a lance tip. There is a strong tendency for the plant to send out sucker shoots from the base of the plant. These should always be kept pruned off.
Attractive scarlet, white, or multi-colored flowers lead to nearly round, two and one-half to five inch-wide fruit. The pomegranate is self fruitful, meaning that it does not need another tree for pollination, and the flowers will accept pollen from themselves or from other flowers brought to them by insects. Cross-pollination increases the fruit set. Wind does not play an important role in pomegranate pollination.
The fruit is surrounded by a tough, leathery skin or rind which is typically yellow inside and light or deep pink or rich red outside. The interior of the fruit is separated by white, spongy, bitter tissue into compartments packed with sacs filled with sweetly acid, juicy, red, pink or whitish pulp. In each sac there is one angular seed. High summer temperatures are essential during the fruiting period to get the best flavor.
The fruit of the ‘Wonderful’ variety, the variety most often planted in Arizona, matures and is ready for harvest in the fall, usually in November, although some other varieties may mature sooner. The fruits are ripe when they have developed a distinctive color and make a metallic sound when tapped. If you are in doubt of the ripeness of the fruit, pick one and test it before harvesting the rest of the fruit from the tree.
Once off the tree, the pomegranate can be stored at a temperature of 32°to 41°F. Some have been able to keep the fruit in storage for up to seven months within this temperature range and at 80 to 85% relative humidity without shrinking or spoiling. The fruits improve in storage, becoming juicier and more flavorful so don’t be in a hurry to use them up. Be sure and save some for later.
The fruit can be eaten right off the tree by deeply scoring the shell several times vertically and then breaking it apart. The clusters of juice sacs are then lifted out from the rind and eaten. The sacs also make an attractive garnish when sprinkled on various dishes.
Pomegranate fruits are often used for juice. After removing the sacs, run them through a basket press or by reaming the halved fruits on an ordinary orange juice squeezer. Another option begins with warming the fruit slightly and rolling it between the hands to soften the interior. A hole is then cut in the stem end and the fruit is placed on a glass to capture the juice as it runs out. Squeeze the fruit from time to time to get all the juice. The juice can be used as a fresh juice, to make jellies, sorbets or cold or hot sauces, and to flavor cakes, baked apples, and other specialties. Pomegranate syrup is sold commercially as grenadine. Pomegranate has been found to be relatively high in antioxidants, compounds that help protect the body from disease.
The pomegranate does best in well-drained ordinary soil, but also thrives in saline soils or even rock strewn gravel. In Arizona, the trees should be lightly fertilized with two to four ounces of ammonium sulfate or other nitrogen fertilizer once during each of the first two springs after planting. At maturity, the tree will do well with three applications of nitrogen fertilizer spread out over the growing season. Fertilize it the same as you would a citrus tree. The trees also respond to an annual mulch of rotted manure or compost.
Once established, pomegranates will take considerable drought, but for good fruit production they must be irrigated regularly. Inconsistent irrigations will cause the fruit rind to split open and allow the entry of insects and diseases. The optimal watering cycle for pomegranates is once a month in the cooler time of year. Once daytime temperatures are consistently above 85 degrees Fahrenheit, then the trees need to be irrigated every 10 to14 days. A good deep watering needs to wet the soil at a depth of two to three feet.
Trees planted during the hot months should be watered every day for the first two weeks to encourage root growth. Afterwards, particularly after new leaf growth begins, the irrigation cycle can gradually be cut back to the normal rotation.
New plants should be pruned back when they are about two feet high. From this point you should allow four or five shoots to develop, but make sure that they are evenly distributed around the stem to keep the plant well balanced. These shoots will develop into scaffold branches that will bear the fruiting wood. Scaffold branches should never be lower than one foot above the ground. Any shoots or branches below this should be considered suckers and removed.
As new branches develop from off the main scaffold branches, make sure to shorten them during January or February each year for the first three years to encourage the maximum number of new shoots on all sides, prevent straggly development, and achieve a strong well framed plant. After the third year, only suckers and dead branches are removed. Since the fruits are borne only at the tips of new growth these extra branches will increase the fruit yield.
The pomegranate can be raised from seed but the plant that results may not have the same characteristics of its parent. For that reason, most new plants are made from cuttings. Pomegranate cuttings root easily and plants from them bear fruit after about three years.
To take cuttings, cut sections of mature, one-year old wood twelve to twenty inches long and remove all of the leaves. Treat the bottom end of the cuttings with rooting hormone and insert about two-thirds their length into the soil or into some other warm rooting medium. Plants can also be air-layered but grafting is seldom successful. Keep the medium well watered and warm and soon roots will form. These cuttings can then be transplanted into place.
When transplanting a pomegranate tree, choose a location with full sun with soil that drains well. The optimal times to transplant trees are in March or October.
Pomegranates are relatively free of most pests and diseases. Minor problems are leaf and fruit spot and foliar damage by white flies, thrips, mealybugs and scale insects, but the roots are seldom bothered by gophers.
Pomegranates can be planted close together for windbreaks, hedges and screens or planted by itself to make a highly decorative accent plant in the landscape. Pomegranates should be placed in the sunniest, warmest part of the yard or orchard for the best fruit, although they will grow and flower in part shade.
The unique taste of the pomegranate fruit, along with its hardiness and attractive flowers, make this plant a good choice for any desert landscape.
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85122
Voice: (520) 836-5221, 227
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Wednesday, June 19, 2013
Home Landscapes: Are They Really Important?
A garden or landscape costs time and money to install. They can be a hassle to properly maintain. Do we really need one? Should we just let the yard go, save the water, and avoid the time and effort required to keep it in shape?
More and more people are asking these questions of themselves as they weigh the costs of installing and maintaining home landscapes. Water, fertilizers, and other inputs can be quite expensive and the work involved in maintaining an attractive, functional landscape can take up time and energy that could well be spent in leisure or other pursuits. In times of economic downturn, these challenges can push the desire for a home landscape way down the list of things to do each day. Unfortunately, in making the decision to ignore or neglect the landscape, they may actually be charging themselves other hidden costs.
Property values are one of these hidden costs. When a home is sold, not only is the condition of house evaluated, but also the outdoor living spaces associated with the home. The presence of trees and shrubs, and their overall health, could be key to placing a “sold” sign on the property. The total value of the property, the amount that the home is sold for, often improves with an attractive landscape.
Another hidden cost can be found in the monthly power bill. The desert Southwest receives more sunshine than any other part of the United States. Pinal County receives more than 80 percent of possible sunshine each year. While the winter sun provides enough warmth to make outdoor activities pleasant and helps heat the interior of buildings, the brilliant summer sunshine quickly brings indoor temperatures to intolerable levels. When that happens, we turn on the cooler. Cooling buildings in the desert is always an expensive process.
Interior temperatures result not only from direct solar gain to the building itself, but also from the accumulation of external heat in the surrounding outdoor areas. The warmer the ambient environment surrounding a building, the warmer will be the interior temperature. Heat radiated from outdoor hard surfaces, such as concrete, roofing, paved streets, and patio surfaces are part of the problem. External temperatures are only made worse when unshaded soil is covered with stone mulch or cobblestone. Even bare soil can present a problem.
Heat gain around our homes can be counteracted by installing and correctly maintaining good outdoor landscapes. Plants cool by reflecting the sun’s rays away from buildings and shading outdoor living areas. While unshaded walls absorb heat from the sun’s rays and transmit the heat to the interior of the building, landscape plants can intercept the sunlight and put it to good use. In this way plants can help keep our homes and outdoor living spaces cool. Wise placement of shade trees and vines can result in significant reductions in the high cost of cooling homes and commercial buildings.
Consider these facts. A dense shade canopy will screen out at least 80 percent of the solar radiation that falls on a human being, outdoor living area, or buildings in our area. A wall in full sun transmits three times the heat of a shaded wall while an unshaded roof adds twice the heat of a shaded one to the interior of the structure. Shading can reduce maximum high temperatures inside a typical house by 20 percent. A quality landscape will be designed and maintained to provide maximum shading.
Another hidden cost is air quality. As more and more people have found the wonderful qualities associated with living in Pinal County, air quality in many areas has taken a nose dive. The pending action by the federal Environmental Protection Agency to address air quality problems in western and southern Pinal County is a good example of this problem. As we evaluate the overall air quality problems, high on the list of particulate matter found in our air are particles of dust blown into the air by our occasionally nasty winds and traffic on bare soil.
Dust in our air does indeed come from many sources, but homes without landscaping, particularly those with bare exposed soils, can have a staggering effect on air quality, at least in the micro environment. Bare soils are particularly bad when they carry traffic, such as vehicles driving on bare soil. Properly designed and maintained landscapes can minimize the loss of loose soil from the surface of the ground and help control dust around our homes.
Finally, homes that are not maintained and/or have landscapes that are either nonexistent or ignored for can indicate a lack of interest in our living environment. Where lack of interest prevails, crime seems to follow. So, indirectly, well maintained homes and landscapes can help reduce crime in an area. This, in part, occurs because a sense of pride and ownership in our homes, even in rentals, tends to make us less tolerant of crime. The increased neighborhood good will and community pride engendered by nice looking homes indoors and out increases a sense of belonging that often times results in a corresponding drop in crime statistics in an area.
No doubt we will find other “hidden costs” associated with abandoned or non-existent landscaping as we begin to search for them. The choice is ours, however, whether or not we will allow those costs to accrue against us and our property. Can’t we take a few minutes and assess the condition of our landscapes? If there are areas where work is needed, let’s invest some time and money to improve the living conditions for us and our neighbors.
In summary then, we ask ourselves the question: “Is it possible to have a low cost, attractive landscape without taking a lot of time, money, and effort?” Yes, there indeed there are options. Dust control and a finished look can be achieved simply by laying down a simple crushed rock mulch on the surface of the soil. Some people have chosen this route and have found that it suits their needs. That is option one.
Adding shade and esthetics will require the presence of plants, generally trees, shrubs, and other plants. Since water is always an issue in desert areas, and especially during drought conditions, we ought to select these plants from desert-adapted low water use plants. That is option two.
If you choose this option, please make sure that you give your plants good care and frequent irrigations to keep them healthy and productive.
In today’s environment, and for the good of the community, urban landscapes do matter. With some input and initial labor, a functional landscape can be created and enjoyed not only by ourselves, but by the community at large.
If you have questions, or need more information, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture, Pinal County
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85122
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
More and more people are asking these questions of themselves as they weigh the costs of installing and maintaining home landscapes. Water, fertilizers, and other inputs can be quite expensive and the work involved in maintaining an attractive, functional landscape can take up time and energy that could well be spent in leisure or other pursuits. In times of economic downturn, these challenges can push the desire for a home landscape way down the list of things to do each day. Unfortunately, in making the decision to ignore or neglect the landscape, they may actually be charging themselves other hidden costs.
Property values are one of these hidden costs. When a home is sold, not only is the condition of house evaluated, but also the outdoor living spaces associated with the home. The presence of trees and shrubs, and their overall health, could be key to placing a “sold” sign on the property. The total value of the property, the amount that the home is sold for, often improves with an attractive landscape.
Another hidden cost can be found in the monthly power bill. The desert Southwest receives more sunshine than any other part of the United States. Pinal County receives more than 80 percent of possible sunshine each year. While the winter sun provides enough warmth to make outdoor activities pleasant and helps heat the interior of buildings, the brilliant summer sunshine quickly brings indoor temperatures to intolerable levels. When that happens, we turn on the cooler. Cooling buildings in the desert is always an expensive process.
Interior temperatures result not only from direct solar gain to the building itself, but also from the accumulation of external heat in the surrounding outdoor areas. The warmer the ambient environment surrounding a building, the warmer will be the interior temperature. Heat radiated from outdoor hard surfaces, such as concrete, roofing, paved streets, and patio surfaces are part of the problem. External temperatures are only made worse when unshaded soil is covered with stone mulch or cobblestone. Even bare soil can present a problem.
Heat gain around our homes can be counteracted by installing and correctly maintaining good outdoor landscapes. Plants cool by reflecting the sun’s rays away from buildings and shading outdoor living areas. While unshaded walls absorb heat from the sun’s rays and transmit the heat to the interior of the building, landscape plants can intercept the sunlight and put it to good use. In this way plants can help keep our homes and outdoor living spaces cool. Wise placement of shade trees and vines can result in significant reductions in the high cost of cooling homes and commercial buildings.
Consider these facts. A dense shade canopy will screen out at least 80 percent of the solar radiation that falls on a human being, outdoor living area, or buildings in our area. A wall in full sun transmits three times the heat of a shaded wall while an unshaded roof adds twice the heat of a shaded one to the interior of the structure. Shading can reduce maximum high temperatures inside a typical house by 20 percent. A quality landscape will be designed and maintained to provide maximum shading.
Another hidden cost is air quality. As more and more people have found the wonderful qualities associated with living in Pinal County, air quality in many areas has taken a nose dive. The pending action by the federal Environmental Protection Agency to address air quality problems in western and southern Pinal County is a good example of this problem. As we evaluate the overall air quality problems, high on the list of particulate matter found in our air are particles of dust blown into the air by our occasionally nasty winds and traffic on bare soil.
Dust in our air does indeed come from many sources, but homes without landscaping, particularly those with bare exposed soils, can have a staggering effect on air quality, at least in the micro environment. Bare soils are particularly bad when they carry traffic, such as vehicles driving on bare soil. Properly designed and maintained landscapes can minimize the loss of loose soil from the surface of the ground and help control dust around our homes.
Finally, homes that are not maintained and/or have landscapes that are either nonexistent or ignored for can indicate a lack of interest in our living environment. Where lack of interest prevails, crime seems to follow. So, indirectly, well maintained homes and landscapes can help reduce crime in an area. This, in part, occurs because a sense of pride and ownership in our homes, even in rentals, tends to make us less tolerant of crime. The increased neighborhood good will and community pride engendered by nice looking homes indoors and out increases a sense of belonging that often times results in a corresponding drop in crime statistics in an area.
No doubt we will find other “hidden costs” associated with abandoned or non-existent landscaping as we begin to search for them. The choice is ours, however, whether or not we will allow those costs to accrue against us and our property. Can’t we take a few minutes and assess the condition of our landscapes? If there are areas where work is needed, let’s invest some time and money to improve the living conditions for us and our neighbors.
In summary then, we ask ourselves the question: “Is it possible to have a low cost, attractive landscape without taking a lot of time, money, and effort?” Yes, there indeed there are options. Dust control and a finished look can be achieved simply by laying down a simple crushed rock mulch on the surface of the soil. Some people have chosen this route and have found that it suits their needs. That is option one.
Adding shade and esthetics will require the presence of plants, generally trees, shrubs, and other plants. Since water is always an issue in desert areas, and especially during drought conditions, we ought to select these plants from desert-adapted low water use plants. That is option two.
If you choose this option, please make sure that you give your plants good care and frequent irrigations to keep them healthy and productive.
In today’s environment, and for the good of the community, urban landscapes do matter. With some input and initial labor, a functional landscape can be created and enjoyed not only by ourselves, but by the community at large.
If you have questions, or need more information, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture, Pinal County
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85122
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Tuesday, June 18, 2013
Growing Plants in a Desert Environment
It is a common lament made by those who are trying to grow plants in the desert for the very first time.
“Where I lived before, I could just throw out the seeds and everything would grow, but here, in the desert, the plants die, no matter what I do!”
I know many people are frustrated in their attempts to grow healthy, vigorous plants, because I hear from them on a regular basis. You may be one of them.
You plant, water, fertilize, and kindly talk to your plants even, but they do not seem to respond, no matter what you do. Unfortunately, it is a true but sad state of affairs. Newcomers to desert gardening, and many old-timers, often find frustration before they find success.
I want to tell you, though, there is hope! Once you become accustomed to the rules governing desert gardening, there is no reason why you cannot join the ranks of those who find growing plants in Southern Arizona an extremely rewarding experience.
The desert is an ideal place to raise fruits, vegetables and ornamental plants. Successful desert gardeners enjoy lush, thriving landscapes and beautiful flower beds. Others enjoy producing much of their own food in successful, healthy gardens. There are three reasons why gardening in the desert can be a satisfying experience.
First, the environmental factors that make Southern Arizona a desert are the same factors that allow a wide variety of plants to be grown in our area. Fruits from apples to lemons and ornamentals from pines to palms can be successfully cultivated. The almost unlimited possibilities have produced landscapes of great variety and interest.
Second, the exact same environmental conditions also allow a year-long growing season. With the correct cultural practices, fresh vegetables can be harvested all year long; beautiful, fresh cut flowers can grace an indoor table every month of the year and turf areas can be green and lush twelve months out of the year. Many area gardeners find the unlimited possibilities both challenging and satisfying.
Finally, the cultural practices necessary to successfully grow garden and landscape plants have been worked out and published for all to know. By learning how to deal with the environmental conditions and by carefully adhering to correct gardening principles, most people should have little trouble enjoying the fruits of their labors.
Assuming that you have bought into believing that success is possible, we are ready to address some of the more important factors that sometimes get in the way of healthy gardens and landscapes. These factors generally revolve around climate and soil.
Southern Arizona’s climate is determined by its latitude, elevation and geography. The latitude, or the distance from the earth’s poles, determines the amount of solar radiation, or sunlight, that a location receives. Solar radiation is critical because it drives photosynthesis, the life process that is so necessary for plant growth. The more solar radiation, the more vigorous the growth of plants. Since we are closer to the equator than many parts of the country and because of our generally bright, cloudless days, we receive more solar radiation.
Elevation has a great effect upon our climate. Take temperature, for example. Generally, the higher the elevation in Arizona, the lower the average temperatures, both during the day and night. At our relatively low elevations, warm temperatures create a year round growing season.
Every plant has an upper limit and a lower temperature limit. In our desert, both extremes can affect plant health and growth. It is just as important to protect our plants from the high temperatures of summer by watering correctly as it is to protect tender young plants from frosts in the winter. Plants cool themselves by releasing evaporated water through tiny pores on the bottom of their leaves and the release has the same effect as a swamp cooler in our homes. If plants run short of water, they die.
Nighttime temperatures also influence the growth of plants. Some plants, such as our winter vegetables, do best when night temperatures are around 50 degrees F., while others do best when the temperatures are 60 degrees F. or higher. Bermudagrass, for example, usually does not start to grow well in the spring until night temperatures reach 60 degrees F.
Rainfall, another climatic factor, is almost always insufficient to grow plants. Many make this mistake, even with supposedly desert hardy low water use plants. To maintain good plant health, rainfall almost always must be supplemented with irrigation, especially when plants are young and just getting started. Proper irrigation is essential for good plant health.
Humidity affects the health of plants in may ways. On the positive side, low humidity stifles the growth and development of many plant diseases. For this reason, plants growing in the desert are often disease free as compared with similar plants growing in a more humid environment. On the down side, the low humidity of June and July means that plants must be irrigated more frequently and with greater amounts during those months in order to keep them healthy.
Wind can definitely be a factor. The strong, dry winds of the desert can quickly dry out tender plants and send them into a tailspin of leaf injury and dessication. In addition, most people have seen the flotsam and jetsam of broken branches and tipped over trees after our summer storms. Proper irrigation, correct staking and good pruning techniques will take care of most wind issues.
Geography, the features of the land such as mountains and valleys, affects microclimates as well as soil. Microclimates are pockets and places where climatic conditions vary somewhat from the norms of the desert climate. Planting strawberries on the north side of a home or fence will often allow them to grow through the summer where a south facing exposure would probably kill them off during the warm months.
Our geography also determines many of the soil factors that impact plant growth. The broad, flat valley floors where most people live were developed though many years of erosion that brought soil particles down from the surrounding mountains to fill the low lying basins. Because of this, there is a wide variety of soil types that affect plants differently and these must be understood to successfully manage the growth and development of plants. Alkali, salinity, low nitrogen fertility, pH, caliche and compaction all find their roots in the dry climate of the desert.
While there is not time, nor space, to talk about all of the factors in detail, it is important to be aware of them and to take the time to know how to deal with them. Let’s continue to talk about them in the future.
Success is possible in growing healthy and productive landscape and garden plants. The most important rule of desert gardening and landscaping is to learn how to work with the environment instead of against it.
If you have questions, or you would like more information on any of these topics, visit with one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture, Pinal County
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85222
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
“Where I lived before, I could just throw out the seeds and everything would grow, but here, in the desert, the plants die, no matter what I do!”
I know many people are frustrated in their attempts to grow healthy, vigorous plants, because I hear from them on a regular basis. You may be one of them.
You plant, water, fertilize, and kindly talk to your plants even, but they do not seem to respond, no matter what you do. Unfortunately, it is a true but sad state of affairs. Newcomers to desert gardening, and many old-timers, often find frustration before they find success.
I want to tell you, though, there is hope! Once you become accustomed to the rules governing desert gardening, there is no reason why you cannot join the ranks of those who find growing plants in Southern Arizona an extremely rewarding experience.
The desert is an ideal place to raise fruits, vegetables and ornamental plants. Successful desert gardeners enjoy lush, thriving landscapes and beautiful flower beds. Others enjoy producing much of their own food in successful, healthy gardens. There are three reasons why gardening in the desert can be a satisfying experience.
First, the environmental factors that make Southern Arizona a desert are the same factors that allow a wide variety of plants to be grown in our area. Fruits from apples to lemons and ornamentals from pines to palms can be successfully cultivated. The almost unlimited possibilities have produced landscapes of great variety and interest.
Second, the exact same environmental conditions also allow a year-long growing season. With the correct cultural practices, fresh vegetables can be harvested all year long; beautiful, fresh cut flowers can grace an indoor table every month of the year and turf areas can be green and lush twelve months out of the year. Many area gardeners find the unlimited possibilities both challenging and satisfying.
Finally, the cultural practices necessary to successfully grow garden and landscape plants have been worked out and published for all to know. By learning how to deal with the environmental conditions and by carefully adhering to correct gardening principles, most people should have little trouble enjoying the fruits of their labors.
Assuming that you have bought into believing that success is possible, we are ready to address some of the more important factors that sometimes get in the way of healthy gardens and landscapes. These factors generally revolve around climate and soil.
Southern Arizona’s climate is determined by its latitude, elevation and geography. The latitude, or the distance from the earth’s poles, determines the amount of solar radiation, or sunlight, that a location receives. Solar radiation is critical because it drives photosynthesis, the life process that is so necessary for plant growth. The more solar radiation, the more vigorous the growth of plants. Since we are closer to the equator than many parts of the country and because of our generally bright, cloudless days, we receive more solar radiation.
Elevation has a great effect upon our climate. Take temperature, for example. Generally, the higher the elevation in Arizona, the lower the average temperatures, both during the day and night. At our relatively low elevations, warm temperatures create a year round growing season.
Every plant has an upper limit and a lower temperature limit. In our desert, both extremes can affect plant health and growth. It is just as important to protect our plants from the high temperatures of summer by watering correctly as it is to protect tender young plants from frosts in the winter. Plants cool themselves by releasing evaporated water through tiny pores on the bottom of their leaves and the release has the same effect as a swamp cooler in our homes. If plants run short of water, they die.
Nighttime temperatures also influence the growth of plants. Some plants, such as our winter vegetables, do best when night temperatures are around 50 degrees F., while others do best when the temperatures are 60 degrees F. or higher. Bermudagrass, for example, usually does not start to grow well in the spring until night temperatures reach 60 degrees F.
Rainfall, another climatic factor, is almost always insufficient to grow plants. Many make this mistake, even with supposedly desert hardy low water use plants. To maintain good plant health, rainfall almost always must be supplemented with irrigation, especially when plants are young and just getting started. Proper irrigation is essential for good plant health.
Humidity affects the health of plants in may ways. On the positive side, low humidity stifles the growth and development of many plant diseases. For this reason, plants growing in the desert are often disease free as compared with similar plants growing in a more humid environment. On the down side, the low humidity of June and July means that plants must be irrigated more frequently and with greater amounts during those months in order to keep them healthy.
Wind can definitely be a factor. The strong, dry winds of the desert can quickly dry out tender plants and send them into a tailspin of leaf injury and dessication. In addition, most people have seen the flotsam and jetsam of broken branches and tipped over trees after our summer storms. Proper irrigation, correct staking and good pruning techniques will take care of most wind issues.
Geography, the features of the land such as mountains and valleys, affects microclimates as well as soil. Microclimates are pockets and places where climatic conditions vary somewhat from the norms of the desert climate. Planting strawberries on the north side of a home or fence will often allow them to grow through the summer where a south facing exposure would probably kill them off during the warm months.
Our geography also determines many of the soil factors that impact plant growth. The broad, flat valley floors where most people live were developed though many years of erosion that brought soil particles down from the surrounding mountains to fill the low lying basins. Because of this, there is a wide variety of soil types that affect plants differently and these must be understood to successfully manage the growth and development of plants. Alkali, salinity, low nitrogen fertility, pH, caliche and compaction all find their roots in the dry climate of the desert.
While there is not time, nor space, to talk about all of the factors in detail, it is important to be aware of them and to take the time to know how to deal with them. Let’s continue to talk about them in the future.
Success is possible in growing healthy and productive landscape and garden plants. The most important rule of desert gardening and landscaping is to learn how to work with the environment instead of against it.
If you have questions, or you would like more information on any of these topics, visit with one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture, Pinal County
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85222
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Friday, June 14, 2013
Growing Cacti in Raised Beds
Growing Cacti in Raised Beds
Rick Gibson
Cooperative Extension Agent, Agriculture
Pinal County, Arizona
If you would like to enjoy the colors and textures brought by the many species of cacti but dread the spines, consider a raised bed garden for these prickly plants.
A cactus garden can be a wonderful way to enjoy the colors and textures of cacti in the home landscape, but working around the plants, especially prickly pear and cholla, can be a painful experience. A raised bed cactus garden is a good way to keep hands, arms and feet away from the spines and still experience the many beautiful species of cacti that will grow in this area.
The familiar saguaro, barrel, hedgehog, Mammillaria, prickly pear and cholla cacti are all native to the Sonoran Desert and are well adapted for landscape use in our area. Their presence in a landscape can give that authentic touch of native dignity that seems to legitimize and complement Arizona desert landscapes.
In addition to the native species, there are many non-native species that also do well in the desert environment. Compass barrel cactus, Ferocactus cylindraceus, and the“old man cactus”, Cephalocerus senilis, are examples of species from other areas. A landscape decorated with a mix of these exotic cacti and species from our own Sonoran Desert can be quite interesting and unique.
Because of the way that they are built, and the way that they carry out their life processes, cacti are well adapted to desert living and make good low water use plants. The thick, wax-coated stems of cacti, for example, are quite resistant to moisture evaporation. This ability to protect themselves from significant water loss through their tissues gives them considerable drought tolerance.
Cacti are leafless, but almost all of them have modified stems called spines. These spines can be straight and needle sharp, such as in the hedgehogs, or curved and broadly pointed like the barrel. These modified stems give a measure of protection from the feeding of animals that might be looking for a source of water. They can also cause a painful experience if one gets too close.
The prickly pear and cholla species have the straight defensive spines, but these particular cacti are especially painful because they have a second type of spine. These tiny spines, called glochids, are hair-like whiskers with barbed structures on their surfaces. Almost invisible to the eye, they can be quite painful and troublesome. Many who have experienced these tiny spines have come to appreciate the value of sticky tape and tweezers as they have struggled to remove them from their skin.
It is the presence of spines, especially these glochids, that lead many to shy away from planting cacti in the landscape. A misstep off the path in a cactus garden can lead to a painful encounter with cacti. Dragging hoses to water other landscape plants almost always results in spines becoming attached to the hose. Invariably, these spines will be transferred from the hose to the hands, arms, and legs of whoever might later be coiling the hose for storage.
One way to help prevent these types of encounters and to help keep the proper distance between people and plants is to place the cacti in raised beds. The framework that creates the raised bed will automatically set the limits between space set aside for people and space that is set aside for cacti. The raised bed sends a strong message to all: venture beyond at your own risk.
Besides physically limiting the possibility of people and pets to move into the garden space, the raised bed structure itself creates a barrier that will prevent a hose from being dragged into the cacti and serves as a boundary limit that will protect wheel barrows, electrical cords and other garden tools from coming in contact with the spines. It provides an extra layer of safety.
The raised bed garden also makes an ideal showcase for viewing the cacti. By locating the cacti closer to eye level, it places them in a position where their good points can be more easily seen.
To create a raised bed for cacti, consider using railroad ties placed side by side and end down to create a strong barrier. The ties should be buried about eighteen inches deep into the soil to prevent the weight of the soil inside the bed from pushing out the framework. The height of the bed can vary but probably should not be taller than twenty-four inches or less than twelve. The framework for the bed can be built square for a formal look, or with softened corners for a more natural feel.
Other materials can be used for a raised bed. Decorative or standard concrete blocks, lumber or even old, worn out tires can be painted and stacked in various arrangements to provide an interesting, but effective arrangement.
Soil used inside the garden should drain well. For this reason, it is recommended that soils should contain large amounts of sand. Place the soil in mounds and plant the cacti at the peak of the mound so that water will drain away from the base of the plant. Water accumulating around these plants can cause the base to rot and eventually lead to the death of the plant.
Weeds can cause a huge problem for those working in cactus gardens. Weeds growing in close proximity to spines will be difficult to remove by hand. Locate the garden well away from Bermuda grass lawns to prevent the invasion of this tough weed, and make sure the soil inside the garden is free of nutsedge tubers and other perennial weeds.
Most weeds in a cactus garden can be prevented by placing a one to two inch layer of rock mulch around the plant. Larger rock, such as 1.5 inch leach rock, makes the best mulch, but other sizes and colors will also work. The use of plastic on the surface of the soil under the rock mulch is not recommended. It prevents surface water from sinking into the root zone and with each passing dust storm supports the accumulation of an artificial zone of soil on top of the plastic in which weed seeds can germinate.
With a little time, energy and know how, a raised bed garden will define the safe boundary between people and cacti and, at the same time, show off the various species in an attractive way.
If you have questions, you can reach one of the Master Gardeners at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85222
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Monday, June 10, 2013
Container Gardening Offers Many Benefits
Container Gardening Offers Many Benefits
Rick Gibson
Cooperative Extension Agent, Agriculture
Cooperative Extension Agent, Agriculture
Pinal County, Arizona
As residential lots get smaller and smaller, there seems to be a growing interest in using containers to grow plants outdoors.
I can see why. Trees, shrubs, flowers, vegetables and vining plants all do well in containers. Containers can be moved around, within reason, to accommodate changing needs and to create different landscape moods. Container gardening creates opportunities where people of all ages can mix and mingle in wholesome activities. Children, as well as adults, often find great satisfaction in mixing soils, potting plants and watching new life begin.
Container gardening is similar in many ways to regular gardening in native soils, but it also is very different. It is these differences that offers challenges, and sometimes failures, to those who attempt to grow plants in containers.
Obvious benefits of gardening in containers are many. One of the greatest is the amount of gardening space required. Because container-grown plants are often kept smaller in size by reduced root volume, less space need be dedicated to plants. Container gardening lends itself well to those living in apartments and to those with small outdoor living space. However, the joy of gardening in containers can be enjoyed by all.
Another great benefit of container gardening is that it avoids all of the problems and pitfalls of gardening in our alkaline desert soils. Because container gardening allows us the opportunity to select our own potting mixture, we can control the nature and chemistry of the root environment and avoid the common problems of salt, caliche, and low fertility found in our native soils.
Container plants also provide great flexibility in decorating for special events and for special needs. Many have discovered the potential provided by container plants for enhancing the appearance of outdoor property for weddings, outdoor parties and other activities. Many also find it easy to add attractive color and variety to the property when a home is up for sale.
A final benefit of container-grown plants is the potential protection that containers can provide from gophers, ground squirrels and rabbits that sometimes ravage soil-grown plants in outlying areas near non-developed areas.
Just about any plant, even trees with the correct-sized pot, can be grown in containers. Plants that grow rapidly actually seem to do best. Tomatoes, eggplant, peppers, melons, and leafy vegetables are some of the edible plants that can flourish in containers.
With the exception of metal, any container will do. Metal containers get too hot during the summer and damage tender roots and lower shoots. Make sure that the container is deep enough to hold sufficient potting soil to support plant growth. It really doesn’t matter how attractive the container is. Less attractive containers can be hidden behind more attractive pots as plants are grouped together.
Use a standard potting soil. Regular desert soil, dug right out of the garden, will carry weed seeds and disease pathogens and these problems will be magnified in pots. Most potting soils purchased commercially have either been well composted to eliminate weed seeds and disease organisms or have been sterilized. A good potting mix would combine equal amounts of compost, peat moss or vermiculite and pumice. While expensive, pumice is useful because it holds water well and helps provide drainage and aeration. It also can help prevent compaction as the mix dries. Regular sand can take the place of pumice, but make sure that it is well washed before use.
Every container should have good drainage out the bottom. Drainage is essential because of the root’s need for air. A good mix will be about 50% solid material and 50% water and air. The spaces between the solid matter is where the water and air are found. Obviously, when we water, most of the air in the mix is driven out. As the plant uses the water in the soil or as the water evaporates from the surface of the mix, air will follow down through the spaces. Ideally, there will be both water and air sufficient to maintain the good health of plants. Match the size of the pot with the size of the plant.
Drainage holes in the container can be covered with a shard of pottery, a stone, or a piece of plastic or metal screening to keep the potting soil from dribbling out the bottom.
When selecting plants for container culture, select plants for different colors, types and textures. Plant a trailing vine to an upright stalk. Mix in herbs and perhaps vegetables with grasses and ground covers. Plant annuals together with perennials for an interesting change . Build a trellis for vining plants like beans, cats claw or sweet peas. Experiment with different arrangements and plant types to see what works best for your situation.
Potted plants dry out more quickly than those planted in the ground. Proper timing of irrigations is critical. It helps to group plants of similar need together and then hook up a drip system on a timer to deliver the amount of water at the frequency necessary to maintain good plant health. Many problems associated with container plants can be solved by careful management of water.
Plants in containers also need adequate fertilization. Because the root system is confined to soil within the pot, available nutrients are more frequently mined from the relatively small area. With the exception of cacti and succulents, such as the agaves, add a diluted water soluble fertilizer with each irrigation. The constant but light application will provide the plant with the necessary nutritional needs required for good growth in the containers.
Make sure that the fertilizer applied contains all three of the major nutrients commonly provided by commercial fertilizers. These are nitrogen, phosphorus and potassium. Artificial container soils will not provide large amounts of nutrient and the use of a complete fertilizer will be necessary. The label of the product will tell exactly what nutrients are provided.
When beginning to garden in containers for the first time, it is advisable to start small and work up. There is a knack to growing good plants in containers. To avoid major failures, it is a good idea to work with one or two pots until you are confident that you maintain the plants in good condition.
Container gardening can be an exciting experience for all who love plants. Following a few basic rules will help bring success.
For more information on how to garden in containers, ask for a copy of the Cooperative Extension leaflet, “Growing Vegetables in Containers”. If you have questions, you can reach a Master Gardener at the Cooperative Extension office, 820 E. Cottonwood Lane, Building C, in Casa Grande. The telephone is (520) 836-5221, extension 204. The author’s email address is gibsonrd@ag.arizona.edu.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
Extension Agent, Agriculture
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, Arizona 85222
Voice: (520) 836-5221
Fax: (520) 836-1750
email: gibsonrd@ag.arizona.edu
Monday, June 3, 2013
Ironwood Trees in the Landscape
Ironwood Trees in the Landscape
Rick Gibson
Cooperative Extension Agent, Agriculture
Pinal County, Arizona
Let me give you a common scenario that I see way too often.
A homeowner wants to lower his or her monthly water bill and decides to do it by cutting back on outdoor landscaping. In a moment of decision, the outdoor irrigation system is shut off and, just like that, the water bill begins to drop. Unfortunately, a few weeks or months later, the plants begin to turn yellow and die.
As the plants begin to shed leaves, the amount of shade provided by the plants begins to diminish and sunlight begins to break through onto graveled yard surfaces and structural walls. The increased sunlight raises the temperature of these hard surfaces. With increasing heat radiating back into the environment, the home owner begins to notice an increase in the power bill as the air conditioning unit works overtime to keep the home cool. Seeing the electricity bill, the homeowner recognizes the problem, taps the head and says, “What was I thinking!”
Trade offs between water and power bills are not uncommon as we struggle to balance between our need to conserve precious resources and the rigors of every day life. However, we do not have to settle for a bare, unattractive yard just to save money. By using plants that get by with a minimum of water, we can lower water and electricity bills and still have pleasing outdoor living areas.
Because of their size, trees use a large percentage of the water in a landscape so one area where we can cut back on water is to choose water stingy trees for landscape use. One of the stingiest of low water use trees is the local desert ironwood, Olneya tesota. It is a hardy, well-adapted, handsome plant that works exceptionally well in a low water use landscape. It takes full sun, has many landscape uses, and gets by on very little water.
A member of the legume family, it has the typical compound leaves of the mesquite and palo verde family. A compound leaf is one that has a central stalk, called a rachis, and along the stalk are little leaflets that together form the leaf. These leaflets are a striking gray-green color and are typically larger than the mesquite leaflets. The dense canopy gives the ironwood top billing in my book as a screening and shade tree in the landscape. Be careful, though. At the base of each leaf, not leaflet, there are two sharp-pointed spines that can easily prick a finger.
The tree flowers in the late spring in a showy display of pinkish-lavender sweet pea-shaped flowers, each about one-half inch long. I think the tree is absolutely gorgeous in full bloom. Just before flowering, the tree will give you heart failure as it sheds most of its leaflets. You would think that the tree is dying just to look at it, but not to worry, it is a normal part of the growth pattern for the tree.
The flowers turn into dark brown, fuzzy, two inch-long pods that split open at maturity and let the seeds fall to the ground. The seeds are highly prized by small mammals in the desert for food. They have also in times past been collected and used for food by humans.
Ironwood trees, depending upon soil and water conditions, will grow to between fifteen and thirty feet tall and the same dimensions wide, so in landscape situations it is important to give them enough room to grow. The spines, like many desert trees, can make them formidable so do not plant them next to walkways or other high traffic areas.
The wood in the center of the branch or trunk, as aptly described by its common name, is extremely hard. The wood has been used in the past for arrow heads and other tools. The cured wood is also highly prized as a cooking fuel. It burns hot and Dutch oven enthusiasts appreciate the hot, long lasting coals. The wood is also used by artisans for carving and other uses. The Seri Indians of Mexico have developed quite an art form for their carvings. The wood is heavy, weighing up to 66 pounds per cubic foot. I know of an ironwood dining room table, over eighty years old, that is so heavy that it took a crew of men to move it into place. It has never been moved since!
As a landscape tree, the ironwood has many uses. Because it can be either a single or multi-trunk plant, it can be developed to fit into that special spot made difficult because of angles or corners. It is possible to plant a whole forest of ironwood trees and no two would be the same. It may take some careful pruning, especially early on, to develop and maintain a desired form, but it will be worth the effort later on. Don’t worry if the branches tend to grow up while the tree is young, they will begin to spread as the tree matures.
In the wild, ironwood trees grow near washes or dry stream beds where deep water is usually available. This means that it will require some water to do well, a deep irrigation once or twice a year at maturity will probably be enough, but the naturally slow growing tree will hasten its growth with more frequent irrigations, especially during the summer.
Beside its trunk shape, the ironwood also has other characteristics that make it valuable as a landscape plant. Its dense canopy of leaves makes it ideal for screening, background, and shade uses. Its flowers provide spring color. It is excellent as a thorny barrier to reduce traffic flows or for security, and its striking appearance makes it valuable as a specimen plant.
The tree requires full to reflected sunlight so it should be placed in a location where it will not be shaded by other plants. It performs well under harsh growing conditions but it is frost and freeze sensitive so it should be planted in regions where winters are warm enough for citrus. Since it prefers a soil with good drainage, it is not a good choice when you are dealing with a clay or caliche soil.
If you intend to plant your ironwood tree from seed, it will be important to scarify the seed either by running them through a rock tumbler filled with sand or by using a file to cut through the hard seed coat. Insects usually are not a problem but mistletoe infestations can distort and weaken branches. Mistletoe seeds are usually spread from tree to tree on the feet of birds so most infestations occur most frequently on larger trees that are apparently more attractive to the animals. Watch for signs of mistletoe plants and cut them out early.
The ironwood tree offers many benefits as a low water use landscape tree and can provide color, texture, shade, and screening to any landscape.
The University of Arizona is an equal opportunity, affirmative action institution. The University does not discriminate on the basis of race, color, religion, sex, national origin, age, disability, veteran status, or sexual orientation in its programs and activities.
Rick Gibson
University of Arizona Cooperative Extension
820 E. Cottonwood Lane, Building C
Casa Grande, AZ 85222
(520) 836-5221 ext. 227
(520) 836-1750 - Fax
gibsonrd@ag.arizona.edu
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