Mistletoe: An Enemy to Plants

Because they have the unique ability to take energy directly from another plant, the various species of mistletoe can cause the slow, steady decline of host trees and shrubs.

Mistletoes are perennial, shrubby, woody or semi-woody flowering plants that attach themselves to other plants and steal water and nutrients from the host plant.  Because they are dependent upon these host plants for nourishment, they are called parasites.  Unlike dodder, which lacks any ability to produce food for itself, the mistletoes do contain the green pigment chlorophyll that allows them to manufacture food from the energy of the sun. 

In the desert Southwest, there are about a dozen different species of mistletoe that affect trees and shrubs.  Each of these species have the ability to invade the living tissue of host plants and extract water and nutrients for their own growth and development.  It is this unceasing loss of strength, coupled with the twisting and distortion of branches caused by the mistletoe that can eventually lead to the decline and sometimes death of trees and shrubs.

The traditional European mistletoe is Viscum album, but in the United States two genera, Arceuthobium and Phoradendron are the representatives of the family.  Arceuthobium species are dwarf mistletoes and are weak, herbaceous plants with leafless yellow-green to orange stems.  These mistletoes parasitize pines and junipers all across the Southwest.

Members of the Phoradendron generally have well-developed leaves on strong, shrubby, almost woody stems.  Some species have large, yellow-green leaves while other species are essentially leafless.  The common desert mistletoe that infests many of the desert legume trees like palo verde, mesquite, and ironwood has only scale-like leaves.  The large-leafed yellow mistletoe is often picked and sold during the holiday season as a way to steal a kiss from someone special.  It is most commonly found on riparian softwood trees like cottonwood, sycamore, willow and ash.

Most mistletoe species produce small white to pinkish or green-tinged berries, whose single hard seeds are surrounded by fleshy, sticky pulp.  The fruit seems irresistible to birds, who then redistribute the seeds to new locations, not only through their droppings, but also by inadvertently carrying the sticky seeds on their beaks and feet.

While otherwise healthy host plants may seem to tolerate one or two mistletoe plants, the parasitic plant’s ability to effectively produce and disperse seeds all but insures the spread of the infestation and the slow decline and even death of the host plant.  The weakening, disfigurement and eventual death of shade, food and lumber producing trees represents a significant worldwide economic loss each year.

Control of parasitic plants is often difficult.  The easiest and most common method of control is to simply prune or break off the plants.  This is best done before flowering to prevent the development and dispersal of seeds.  Removal of the parasites also helps to reduce the drain on the host tree as pruning prevents the loss of valuable water and nutrients from the host. 

Unfortunately, mistletoe pruned in this manner usually does not remove all of the parasitic plant, and the parasite will often grow back quickly.  For this reason, frequent pruning is often necessary.  To prevent frequent regrowth, remove the mistletoe as close to its point of attachment as possible.  Some bark tissue may safely be removed during this process, but try not to cut too deeply, or the branch may snap under its own weight or in a wind.

A more permanent step would be to completely prune away infected limbs and branches up to 12 or more inches below the mistletoe point of attachment. This type of pruning works well for younger clumps of mistletoe, but it cannot be done on older growth mistletoe, or where the mistletoe is on large, often essential limbs.  Be sure to prune the infected limbs back to their point of attachment with a larger branch or the trunk.  Never leave the stub end of a branch that could invite the entry of other diseases and wood-destroying insects.

Where infestations occur on essential branches or on the trunks of trees, some measure of control can be achieved by pruning the offending mistletoe back flush with the tree and then wrapping the exposed points of attachment with dark, light-excluding plastic sheeting.  The lack of light on the remaining parasite tissue will prevent the regrowth of the pest.  As the mistletoe is deprived of sunlight, the parasite will eventually die.  However, this make take a year or two, so it is important to check the plastic wrap regularly and replace it if it begins to degrade.

Mistletoe is a common pest on local landscape trees, but by careful vigilance and proper tree care much of the damage to, and death of, these valuable plants can be avoided.

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 85222

Voice:  (520) 836-5221

Fax:     (520) 836-1750

email:   gibsonrd@ag.arizona.edu

Date: November 26, 2014

Plants Provide Many Benefits In Our Lives

In a hurry up world where life seems to constantly accelerate and the day-to-day challenges appear to bring ever more stress, plants can impart a sense of needed stability and well-being in our lives. 

There are many scientific studies that indicate a strong relationship between healthy people and exposure to plants, both indoor and out.  Here are some examples taken from a series of articles published just in the January-March 2000 edition of  “HortTechnology”, a quarterly journal for horticultural professionals.

The first example comes from one of the earliest studies looking at the beneficial effects of plants.  Patients having a room with a view of trees rather than a view of a brick wall spent almost a day less in the hospital, used fewer doses of strong pain relievers, and received fewer negative comments from hospital staff on their charts.  The study instantly attracted the attention of both the medical community and horticultural researchers.  

In another study, people in an experiment viewed slides of nature scenes with water and vegetation, slides of nature scenes with only vegetation, or slides of urban scenes without vegetation.  When people viewed either of the nature scenes, they exhibited higher alpha brain wave amplitudes than when viewing urban scenes.  

“Okay, Rick, what exactly does that mean?”  Higher alpha brain wave amplitudes are generally associated with lower levels of physiological arousal and higher levels of attentive relaxation.  In other words, those tested were judged to be under less stress.  That is a good thing.  The subjects also reported that the nature slides held their attention better than the urban slides, even though all of the slides were judged to have similar informational content. 
            
One study focusing on college students showed that those performing tasks that required deep mental concentration performed significantly better on some tests when they enjoyed a window room that opened out onto a nature scene than those who had views of scenes dominated by buildings and sidewalks.  Nature scenes seemed to enhance mental attention and reduce fatigue.

A 1996 study asked apartment complex residents about domestic violence.  Respondents lived in public housing and could not choose their apartments.  Some were assigned to live in complexes surrounded by trees, while others were assigned to buildings without green surroundings.  When asked if they had engaged in violence during the past year, 22% of the women interviewed from the apartments without trees said “yes” while only 13% of the women in the apartments surrounded by trees said “yes”.  When asked if they had hit their children in the past year, 14% from the non-green apartments said “yes”, while only 3% living in apartments near trees said “yes”.   

The list of studies goes on and on, here in the U.S., and around the world.  The evidence is quite clear.  Scenes associated with plants can reduce stress, speed healing, enhance workplace productivity and improve the human outlook on life.   

These results have not gone unnoticed.  Around the world, plants are showing up inside public buildings, in malls, in hospitals, and long term care centers.  School gardens are being planted and cared for.  Community gardens, consumer supported agriculture enterprises, and agricultural tourism operations are flourishing.  Adults working in the court systems assign juvenile offenders to work in community gardens.  Yes, horticultural therapy has become a viable tool in the medical field, but it is also key to well being in our every day lives.  

These real benefits, however, are sometimes masked, covered up, if you will, by the very challenges of life that make our involvement with plants so essential.  The bottom line is that we are becoming too busy to garden, to care for house plants and to plant trees and shrubs.  

If we do install landscapes, we often give in to the temptation to make them so labor-free that we do not find the need to interact with them in any way other than in the most brief of encounters.  This may be helpful in our busy worlds, but it is expensive in terms of the very real benefits that could be ours if we regularly went out among our plants.

So, what can you and I do?  There are several ways to enhance our interaction with plants and to improve the surroundings in which we live.

First, bring plants indoors.  Look around the interior living space and search for locations where an indoor plant might fit.  Identify  locations where light, humidity, and temperature conditions fit the needs of the plant.   For example, do not place a boston fern in an area where the cooler or heater vents would blow on the plant and dry it out.  Ferns like moist, humid areas such as in the shower or bath.  

Group indoor plants into natural appearing arrangements that give a sense of the outdoors from which they came.  Such arrangements help create a peaceful, natural feeling similar to that experienced in native environments.

Second, search for ways to make outdoor landscapes user friendly.  Arrange and install outdoor landscapes with the intent that they will encourage human interaction.  Select plants that fit the specific needs of the landscape and of the people that will use it.  Let the landscape be an extension of the home so that it will be an easy and natural step to exit the home and immerse oneself in the outdoors.  A well designed and maintained landscape will entice people indoors to move outside.

Consider placing benches or chairs in strategic locations that invite a passerby to linger and enjoy the setting.  This may be tucked away between trees or behind shrubs away from busy traffic areas, or it may simply be next to favorite flowering shrubs or garden areas.  Such locations encourage introspection and relaxation from busy schedules.

Third, notice the use of plants and natural environments in public places and recognize them for what they bring to those who visit those areas.  Many malls, for example, spend considerable resources to bring the natural environment inside for a peaceful, if not restful, shopping experience.  Encourage businesses and other establishments that you frequent to consider installing plants into their decor.  Tell them about the potential benefits that could come both to them and their customers from the practice.

Fourth, become active in neighborhood and community beautification committees, school garden projects and community garden efforts and encourage the proper use of landscapes and indoor plants in all areas.  Volunteer time not only lifts those served, but also reaps benefits to those serving.

Finally, become informed about plants and the potential benefits that come from human interaction with plants.  Know how to properly select, install and care for indoor and outdoor plants in our harsh, desert environment.  

Healthy plants in our living environment can help all of us accrue actual emotional, physical and psychological benefits each and every day.  The bottom line is, plants help us live better lives. 

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.


-- 

Richard Gibson
Extension Agent, Agriculture
University of Arizona
Pinal County Cooperative Extension Office
College of Agriculture and Life Sciences

820 E Cottonwood Ln, #C
Casa Grande, AZ 85122
Tel: (520) 836-5221 ext. 227
Fax: (520) 836-1750

Plant Pollination Critical

To enjoy fresh fruits and vegetables straight from the garden, we cannot ignore the importance of effective pollination. 

For the many garden plants that produce edible seeds and fruits, pollination is essential.  Plants like cantaloupe, tomato, and apricots will often abort fruit that has not been properly pollinated and seed producing plants like beans, almonds and pecans often end up with empty pods or shells when flowers do not receive their share of pollen.  If plenty of fresh fruit and vegetables are important to us, it is critical that we know about, and correctly manage, the process of pollination.

Pollen is the male particle that carries genetic information used in the production of new plants.  Pollen is produced in the anther or male reproductive structure of flowering plants, and is  transferred, either by the wind, gravity, insects or other agents to the stigma, or female part of the flower.  When the male information is combined with the information provided by the female part of the flower, the process of pollination is complete.  Under normal conditions in native environments, pollination usually is a normal function of nature, and plants are able to progress flawlessly from generation to generation practicing the law of survival of the fittest.  

Occasionally, however, problems can arise. In plants where the pollen from their own male structures fertilize the female structures in the same flower, the process is called self-pollination.  Garden peas, wheat, oats and cotton are examples of common plants that self-fertilize and in most cases, good pollination usually occurs.  Most pollen-related problems in self-pollinating plants are usually related to heat stress where high temperatures sometimes kill the pollen before a transfer of genes can occur.  In home gardens, proper adherence to planting date recommendations will usually prevent pollination problems in self-pollinated garden plants.

Plants that require the transfer of pollen from one flower to another are dependent upon cross-pollination.  This extra step can mean trouble.  If the transfer is interrupted or prevented in any way, the development of fruit or seeds will simply not occur.  

The exchange of pollen during the cross-pollination process is often facilitated by outside agents called pollinators.  When we think of pollinators, most people think immediately of honey bees, and you would be absolutely correct. The honey bee is a most effective pollinator and most of the foods that we enjoy occur because of their hard work.  Citrus, watermelons, apples and many more are all dependent in some way or another on honey bees.  

However, these effective and hard working animals do not have the field, forest or garden to themselves.  There are many other species of bees as well as other insects and animals that help spread pollen from plant to plant.  Some of the more common pollinating agents besides the honeybee include bats on saguaro cacti; birds, especially hummingbirds on many long, tubular-shaped flower plants; and some wasps, flies, moths and butterflies.  In addition to animal pollinators, we cannot forget that the wind also plays a major role in the cross-pollination of many plants.

Generally, plants with inconspicuous flowers which lack petals, odor, and nectar are pollinated by the wind.  Grasses, cottonwoods, elms, walnuts, oaks, pecans and, yes, let’s not forget ragweeds, are all wind pollinated.  Grouping desirable wind-pollinated plants together in blocks will help make sure that proper pollination occurs.  Commercial pecan and pistachio orchards are planted with a row of pollinator trees every so often in the block to ensure good pollination.  

A good garden example is sweet corn.  Because it is wind pollinated, sweet corn must be planted in blocks and not long narrow rows in the garden to ensure the best coverage of pollen onto the developing ears.  Poor pollination in corn will be seen as skips between the kernels at maturity.  Also, similar symptoms can also be seen when temperatures above 100 degrees F kill pollen before pollination occurs.   

Although wind-pollinated plants need not concern themselves with the business of attracting pollinators, it is a different matter for plants that need more than a breezy day to assure that there is a next generation.

Members of the Cucurbitaceae family, like squash, cantaloupe, and watermelon, require the actual movement of pollen from the showy male flowers to the inconspicuous female flowers where the fruit develops.  These flowers are in completely different locations on the plant and reproductive success is entirely dependent upon insect pollinators like honeybees to make the transfer of pollen.   

A pollination problem often shows up among cucurbits in the early spring.  In the desert, we generally plant them early to obtain a yield before the hot weather shows up.  Since bees are sluggish in cold weather, late winter storms arriving during the pollination period can slow down the movement of these pollinators and  result in some flowers not receiving pollen.  Squash and melons that turn brown at the tips and begin to shrivel up soon after fruit set are a direct result of poor pollination. There is nothing that can be done for these aborted fruit but not to worry.  Just wait a little bit.  As the weather warms, pollination gets back on track and plenty of fruit will set later.

Poor pollination can also cause problems in tomatoes.  If the flowers do not properly get pollinated, the plant terminates the flower.  During that process, the aborted flower develops a layer of thin, weak cells across the flower petiole.  Eventually the weight of the flower causes the discarded flower to break off and fall from the plant.  Since tomatoes are wind pollinated, sometimes a good shaking of the vine and the flowers will cause the pollen to shift inside the flower and help pollination.

Another important pollination concept is self-incompatibility.  In all sweet cherries and in many varieties of apples, plums and pears, the pollen produced in anthers of one horticultural variety does not function on stigmas of the same variety, even though the stigmas are in flowers of a different tree.  This self-incompatibility can significantly reduce or prevent the production of fruit during the growing season.  It is for this reason, that pollinator varieties are often recommended for certain plants.  For example, the ‘Anna’ apple will produce some fruit without a pollinator, but does much better when it is sharing pollen with another variety like ‘Golden Dorsett.’  

Once we understand the importance of pollination, we understand the importance of the pollinator.  I have to tell you that we definitely are worried about the future of the honey bee.  If these friends are lost for any reason, we could be in serious hot water when it comes to food on the table.  This is one of the reasons that we are super careful with insecticide applications.  It is important to follow the label directions carefully and avoid applications when the bees are active.  
By studying the biology of our beneficial plants, potential problems can either be headed off or at least understood when they occur.

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, 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.

Richard Gibson
Extension Agent, Agriculture
University of Arizona
Pinal County Cooperative Extension Office
College of Agriculture and Life Sciences

820 E Cottonwood Ln, #C
Casa Grande, AZ 85122
Tel: (520) 836-5221 ext. 227
Fax: (520) 836-1750

Basics of Landscape Design

Fueled by the rapid rate of new home construction throughout Pinal County, landscaping of building lots has become a hot topic of discussion in neighborhoods, plant nurseries and home owner association meetings. 

If you are in the process of creating a new landscape from scratch, or are thinking about giving a new look to an existing landscape, here are some ideas to consider before you turn that first spadeful of soil.

“Get it right the first time!” is an important rule of landscaping.  Landscapes are long term investments that can provide real, tangible benefits in years to come.  Mistakes can be costly and frustrating if plants die or have to be removed for future projects.

The importance of Southern Arizona landscapes can be measured in several ways.  One method is to look at the increase in the property’s value after the landscape is installed and complete.  It is a well known fact that trees and shrubs add value to the home and enhances the investment of the owner.

Another benefit of a well landscaped home is the resale potential.  Owners of properly landscaped homes often find that it is the landscape, all things otherwise equal, that seals the deal when it comes time to sell the home.   

Perhaps the most important reason for spending a little extra time on the outdoor landscaping is best demonstrated during the cooler months of the year when great weather entices parties and family projects outdoors.  Attractive and inviting landscapes can bring pizzaz to desert Southwest living and open up confined indoor living spaces to the outdoors.

The creation of outdoor living spaces can be as simple as the strategic placement of trees and shrubs for shade and screening, or as intricate as a formal garden.  Some may want to attract birds and butterflies while others want a quiet refuge from the hustle and bustle of the day.  There may be an outdoor play area to screen or enhance while others may want their landscape to take on the appearance and function of a carefully decorated outdoor living room.  The secret to unlocking the usefulness and beauty of any landscape is proper design.

Good landscape designs blend the placement of plants with the location and style of new or existing constructed features like gazebos, porches, ponds and decks.  Done correctly, the design will ensure that both plants and features work together to accomplish the desired goal.  Landscape design is, in reality, a type of art that combines the beauty, balance and form of plants with the look and feel of permanent structures to create attractive and pleasant surroundings.

Doing the job too quickly and not putting enough thought into the design are major causes of mistakes in the landscape, and mistakes are often costly in time and money lost.  Placing an invasive tree too close to a septic pool or sewer line is a common error.  Another mistake is to place large plants in tight spots, such as a saguaro cactus underneath the eaves of a home, or a large tree in a crowded area.  These errors often end in damaged structures or upset neighbors.

Proper planning will minimize mistakes.  If you want a professional job, consider hiring a landscape architect or landscape designer.  They have training and experience to help them know what will fit into the available space and how to make good use of plant materials.  The more complex the design of the landscape, the more one needs the help of someone who knows how to do the job right.

There are many great landscapes, however, that have been designed and installed by do-it-yourself gardeners.  If you fall in this category, here are the basic steps that you will need to follow.  

First, draw up an accurate plan to scale showing the location and outline of the house and other permanent structures on the lot.  The drawing should indicate the location and description of existing vegetation, rock formations, changes in grade, direction of slope, sidewalks, storage buildings, patios, pools and gazebos.  These should all be drawn to scale.

Once the rough outline is complete, everyone who will have an interest in the landscape should sit down, children as well as adults, and decide what activities the landscape should support.  Vegetable gardens, flower beds, fruit trees and shade trees may be important.  Is there a need for a playground with swings, or for a sandbox?  All interests, hobbies and needs should be considered, and set down on paper.  From this information will come the ideas for the various functions or activities that will take place in the outdoor setting.

Next, start planning the basic elements of the landscape.  These include the public area that is seen by people on the street, the living area for outdoor activities, and the service area for garbage receptacles, wood piles, stacks of lumber, and other storage functions.  Determine the space that will be needed for each and how their appearance will either be highlighted or screened according to specific need.

Another element to be considered is water use.  In the past, landscapes have not been planned with water conservation in mind and these types of landscapes have often resulted in high water bills.  In today’s world of increasing demand for water resources, landscapes using desert-adapted, low water use plants can help cut the water bill without sacrificing livability, especially if the oasis concept is used.

Oasis-type landscaping concentrates water-loving plants around a central living area such as a small lawn, or a fountain.  As one moves away from the oasis, the plants gradually decrease in water need toward the fringes until the landscape becomes a standard desert-type vegetation requiring little additional water.

Climate and wind control are also important functions of a desert landscape.  Shading, shelter from dust storms, passive heating and cooling, and garden microclimates are types of functions that should be considered.

Plants also make good screens and shelters, not only as foundation plants, but also for privacy.  The proper plant in a given location can not only increase the serenity of a landscape but also add a touch of professionalism to the design.

Once the needs have been determined, it is time to assemble the plan.  Start with the basic outline of the home and essential structures, then begin placing the various landscape elements into that plan. It is always easier to consider the building lot as a cube of space, much like a room.  The ground is the floor, and the property lines are its walls.  The ceiling is the canopy created by structures, tree overhang, or the sky.  A good landscape will be like a well arranged room.  The effect is pleasing and you do not have to stumble over anything to get where you want to go.  

The final plan should be an extension of you.  By selecting the correct plants and arranging them in a workable yet pleasing manner, the finished project will be not only comfortable but satisfying.

If you have questions, you can reach Rick Gibson or 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

University of Arizona 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

Growing Roses In Pinal County

Roses are always a popular flower and this year has been a good year for the colorful flowers.

Roses have many uses in the landscape.  Miniature roses in pots by the front entry, long-stemmed hybrid teas along a foundation, climbers trained over a shady trellis, or a massive color display from cascading canes filled with blossoms are just some of the opportunities that await.  The huge diversity of rose cultivars offers an almost limitless number of landscape possibilities.

Can roses do well in the desert?  The easy answer to that question is absolutely yes!  However, you do have to know what you are doing.  If you are just getting started, though, do not dismay.  When you know a few basic rules, you can still grow a beautiful rose, and then learn as you go.

Roses come in many forms.  One type are the old rose cultivars, ancestors of the modern, large-flowered varieties that we enjoy today.  These heirloom roses have been planted for centuries, but now are found mainly in the gardens of big time rose enthusiasts and in museums.  You may be interested in searching out and planting one or more of these types.

Most people, however, are attracted to the modern rose varieties.  Even still, the selection process can be daunting.  A gardener can select from hybrid teas, climbers, miniatures, floribundas, and grandifloras, to name a few.

Floribundas and polyanthas have gained in popularity in Arizona.  Both produce flowers in clusters.  The floribundas are known for their vigorous growth and profusion of medium to large blossoms.  These plants are very hardy and many varieties bloom almost continuously.  The polyanthas are small-growing bushes with clusters of small flowers and generally are not as hardy as floribundas.

Grandifloras are generally vigorous and tall growing.  The flowers are similar in form to those of the hybrid teas, but are usually borne in clusters, similar to the floribundas.  One benefit of grandifloras is that they have stems long enough for cutting and arranging. 

Hybrid tea roses are among the most popular roses grown in Arizona.  They provide excellent cut flowers, and in the warmer sections of the state, provide vibrant spring and fall color.

Before the hybrid teas arrived on the scene, the hybrid perpetual roses were the most popular roses.  The flowers are large and showy and the plants are vigorous and cold hardy.  Their main period of bloom is in the spring, but some varieties will produce flowers again and again through the growing season.  Hybrid perpetuals need a little more fertilizer and water than the teas.

Climbing roses may be either hybrid teas, hybrid perpetuals, floribundas, or rambler varieties.  All of these have long canes and need special handling.  The flowers may be borne in clusters or on single stems, depending upon the variety and method of training.

Miniature roses are popular because of their colors and smaller blossoms.  They can provide a unique appearance in the landscape that gives both grace and color.  Miniature roses are also well-adapted to container culture.  Limited space allocations make them ideal for patio and townhouse gardens. 

Miniature roses respond to the same basic cultural practices as standard-sized roses but because they are smaller, fertilizer applications should be scaled back accordingly.  Good foliage and bloom capabilities can be maintained by cutting back one-third to one-half several times during the season just after the peak bloom.

Aphids and thrips are the most common pests of roses in southern Arizona.  Aphids are soft-bodied insects that feed through sucking mouthparts and cause small dots of yellow tissue, called stippling, where they feed.  Soap solutions, washing with strong streams of water, and systemic insecticides work well in controlling these insects. 

The thrips insect is the main culprit in causing petals to turn brown along the edges and prematurely drop from the flower.  Thrips are most easily controlled with a systemic insecticide. The quarter-inch long, black, cigar-shaped pollen beetle which is so common in area rose blossoms feeds mainly on plant pollen and is not generally responsible for damaged blooms.

Circle- or oval-shaped pieces of missing leaf tissue that seemingly disappear overnight are the result of the work of leafcutter bees.  These are solitary bees, meaning that they do not form community hives.   Each female cuts and uses the leaf segments to form brood cells in which her eggs develop into adults.  Because neither the bee nor her offspring eat the plant tissue, no systemic insecticides will ever touch the animals.  Contact sprays do not work well either because the bee works so quickly that by the time the insecticide is located and aimed, the damage is done and the bee is gone.

The best solution for leafcutter bees is to diligently search out and destroy the cigar-shaped, one inch long nests before the new adults hatch out.  This will help reduce the total population of bees in the area.  Fortunately, the tissue lost to leafcutter bees is usually not sufficient to damage the health of the plant.

Good plant nutrition is critical for rose health.  Roses, like all plants, need sufficient amounts of the sixteen essential nutrients.  Of these, nitrogen is the one element that requires the most attention.  Our low organic matter soils simply cannot provide sufficient nitrogen on a regular basis to allow a plant to grow and produce normally. 

Nitrogen-based fertilizers should be applied lightly and frequently for best results.  It is better to apply small amounts of fertilizer once each month during the growing season, starting in January and ending in October, rather than a single heavy application once a year.  An application of about two ounces of 21-0-0 or 16-20-0 every six weeks during the growing season starting in early February and ending in mid-October is best for most Pinal County areas.  Two ounces corresponds to about two heaping or four level tablespoons of material.  If you use a phosphorus fertilizer, make sure to work it into the ground with a rake or hoe because phosphorus will not leach into the soil during an irrigation as will nitrogen.

Another key to good rose production is to make sure that the plant gets plenty of water on a frequent basis, especially during the hot, dry summer months.  Deep irrigations that wet the entire root zone will also help leach our harmful salts.  Covering the surface of the soil underneath the bushes with an organic or stone mulch helps slow evaporation and keep the soil cool.

When blossoms are cut from the plant, it is important to use a sharp tool, like a knife, pair of scissors, or pruning clippers.  The cut should be made at a 45 degree angle and just above a node, the point where leaves emerge from the stem.  This will avoid unsightly stub ends on the stems and make it easier for the plant to grow new tissue from the buds located at the node.  Old flowers should be removed, “deadheaded,” promptly to encourage the growth of new blossoms.

Finally, roses like a neutral to slightly acid soil, not the alkaline soils native to the desert.  Regular additions of soil sulfur to the soil will help bring down the pH to a level that will allow the rose plant to tolerate our unfriendly conditions.

With a little know-how and patience, roses can bring lots of color to your 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 85222

Voice:  (520) 836-5221

Fax:     (520) 836-1750

email:   gibsonrd@ag.arizona.edu

Growing Aloe Vera In Desert Landscapes

    

If you are interested in water conservation, and enjoy landscapes that contain plants with eye catching shapes and colors, you may want to think about one of the many species of the genus Aloe.

Most of us know about the medicinal aloe, Aloe vera, but there are others that not only look good, but bring interest and color to the landscape.  By selecting the right type for a particular use or site, you can definitely achieve a unique look in your landscape.

Although the aloes are not native to the desert Southwest, there are many that are well adapted to our environmental conditions.  Most will take the heat just fine, but the fierce sun of our hotter areas can burn the soft, tender tissue.  In Pinal County, it is best to plan on growing them in filtered sunlight or light shade.

All aloe species need a well drained soil.  If their roots stay bathed in water for too long, they can be attacked by soil dwelling root diseases.  Most will survive without much water, but they always look better if they are given an occasional irrigation, especially during the hot, summer months.

Because aloe plants are succulents, fleshy plants with a unique life chemistry, they do not need fertilizer.  Succulents have a way of living that allows them to get by without us adding any additional nutrients beyond that which they can get from the air and soil.

Aloes can reproduce vegetatively, which means that they can spread by forming young baby plants, “pups”, at their base.  Some aloes do this quite aggressively and one cute aloe can quickly turn into a weedy monster.  To keep them under control, plant them in a location where you can place some type of barrier all around them. A sidewalk or concrete barrier in front and a wall behind, for example, will define the space where you want them to be. 

While aloe plants are fairly tolerant to cold temperatures, most are quite susceptible to frost and freeze damage.  It is always a good idea to plan on giving them some protection during the coldest nights.  A cloth covering, such as a bed sheet, quilt or piece of burlap, should be sufficient to protect the more sensitive plants.  Plan on uncovering the plants during the day so that they can continue to make food from the sunlight and to allow the sun’s rays to heat the soil under the plants.  It is this heat trapped under the covering that provides protection during the cold night.

When selecting a planting site outdoors, it is a good idea to keep them well away from turf areas or other grassy plants.  Because they are closely related, weedy grasses like Bermudagrass growing up through an aloe plant will be particularly difficult to remove.  Herbicides that work well at controlling grasses will harm the aloe.  This leaves us with the unpleasant choice of  hand pulling as the only recourse.  Be sure to wear gloves if you have this problem.  The sharp spines on the aloe can be quite unpleasant!

Lets talk now about some of the species that might fit into your landscape.  Because just about everyone knows about Aloe vera, let’s take that one first. It is sometimes sold under a different scientific name,  A. barbadensis.  With either name, it is the same plant.

The medicinal aloe is used frequently in folk medicine as a treatment for burns, bites and inflammation.  Because of its fame, and because it is so common, just about everyone has one growing somewhere.  It grows equally well in containers or free standing in the landscape.  

This plant is one of those aloes that can become a weed quickly.  It forms tight clusters of plants and the colony will continue to expand as long as there is room to grow.  This aloe is definitely one that needs a barrier to keep it under control.

The medicinal aloe has narrow, fleshy, stiffly upright leaves that can grow up to two feet long.  It has yellow flowers on top of a stalk that can reach three feet in height.  Because of its winter hardiness, it is one of the best aloes for the warmer areas of Pinal County.

Among the more striking aloes is the tree aloe, Aloe arborescens.  This one is big! It needs a lot of room to properly grow.  It can reach heights of ten feet and will grow about six feet wide or more. Some older plants have grown to about eighteen feet in width.  I would put it in a corner of a yard where it will have plenty of space and provide a focal point to attract the gaze.  

The tree aloe flowers in the winter with bright yellow flowers in long clusters.  It is not particularly hardy in frosty areas.  The foliage can be damaged by temperatures of 29 degrees F. but can survive temperatures down to 17 degrees F.  This plant is probably best grown in Maricopa or Casa Grande.  In colder areas, such as Coolidge or Florence where temperatures are slightly colder than the western part of the county, you may need to give it a warm microclimate in the yard.  A protected corner, in between houses or other structures or in the midst of other plants might give some added protection.

There are many other aloes, all of which bring just a little different flavor to the landscape.  They come in all sizes.  Here are some which have been recommended for our desert area.

Small aloes that do particularly well in containers include A. aristata or the jeweled aloe, A. distans and the partridge-breast aloe or tiger aloe, A. variegata.

Medium sized aloes that can be grown either in containers or in outdoor planting areas include A. brevifolia, A. nobilis, A. plicatilis, A. saponaria or the soap aloe, A. striatula and A. tenuior.

Large, tree-like plants that probably should only be grown outside include A. arborescens, the tree aloe mentioned earlier,  A. bainesii, A. ciliaris, A. ferox and A. marlothii.  Some, such as A. bainesii, are quite sensitive to frost, so care must be taken in selecting the planting site.

If you are looking to conserve water and want to plant something different, consider planting one or more of the aloes.

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.

-- 

Richard Gibson
Extension Agent, Agriculture
University of Arizona
Pinal County Cooperative Extension Office
College of Agriculture and Life Sciences

820 E Cottonwood Ln, #C
Casa Grande, AZ 85122
Tel: (520) 836-5221 ext. 227
Fax: (520) 836-1750

Water Gardens

Home Water Garden

Rick Gibson
Cooperative Extension Agent, Agriculture
Pinal County, Arizona

Water features can make an excellent addition to a home landscape.  

Imagine sitting outside in a favorite section of your garden listening to the quiet tinkling of water cascading down from a fountain spring into a lily-covered pool.  The images and sounds of falling water have always captivated the human mind, as evidenced by the remains of pools, ponds and waterfalls in gardens from even the most ancient of times.  Just as they have done for generations before, water gardens can bring a unique flavor to your outdoor living area.  

A pool of water with water-loving plants, a few well chosen water features and a school of fish to keep down the insect population are key elements to a water garden.  Many people add a small waterfall to provide sound and a natural feel to the garden. Centered on these basic elements, the size and design of a water garden can be as simple or as complex as the builder desires.  

A water garden does not have to be expensive.  With a relatively simple design and with restraint in shopping, a water garden can cost as little as $100 or less.  Kits that can be purchased from home and garden stores can make installation simple.

Water gardens can bring unexpected benefits to a landscape. A trip to the pond can become an instant biology lesson for children and adults alike. Depending upon their design and construction, water gardens can also double as a birdbath or as a wild animal watering hole.  Many people have been able to get to know their wild desert neighbors by watching the pond early in the morning or at dusk as animals come to get a drink of water.

A good way to decide if a water garden is right for you is to visit places where a garden has been installed and to experience their benefits for yourself.  When you go, pay particular attention to where they have been located in the landscape.  Are they a focal point of the garden that can be seen from the patio, courtyard or the balcony of a home? Perhaps they have been secluded away at the end of a path or in the midst of an oasis-type grouping of plants.

Check the shape of the water garden and see if there is a waterfall or fountain to aerate the water and to provide the effects of moving water. Also pay attention to the type of plants and fish that make up the garden.  Once you have looked at several different gardens you should be able to decide if a water garden is right for you.  

If you are unsure about your ability to properly construct a water garden, there are a number of excellent books and publications on how to plan, install and maintain a water garden that can be a valuable resource and provide good support and ideas from start to finish. 

Water gardens come in many types.  Some people, especially those who are renting, choose to use a variation of a container garden which is portable and easy to maintain. These containers can either be free standing above ground or they can be sunken into the ground and surrounded by rocks and plants to give a more natural feel to the appearance of the garden.

More elaborate ponds can either be raised above ground in attractive frames or can be sunken into the ground for a more permanent and durable construction.  All ponds can be further enhanced with the addition of a fountain, a waterfall or a running creek to provide contrast and a more natural appearance to the garden.  

Probably the most common, permanent water garden is the concrete lined, sunken pond, but the emergence of quality plastic liners and paving stones have given additional options from which the builder of a water garden may choose.  In either case, the principles for installation and care are much the same.

The very first step before making the first purchase or shoveling the first spadeful of soil is to check your community’s building codes for size and depth limitations.  Even if there are no codes to follow, a shallow pond is best if children will be visiting because a pond or other water feature will be like a magnet.  Sooner or later, someone is going to fall in.  A shallow pool allows them the chance to stand by themselves.  For safety’s sake, smaller children and those who are unable to walk should be supervised continually when outdoors.
    
The next step to locate where on the property your water garden should be placed.  Most water plants like full to filtered sunlight so this should be the first consideration.  Avoid deep shaded areas to ensure that the water plants will have vigorous growth.  

Other considerations for placing the pond should include the proximity to a water source, the rockiness of the soil and the availability of an outdoor electrical outlet from which to run electric pumps for fountains. Sharp rocks in the soil can easily cut plastic liners and other equipment.

Once the location has be determined, it is time to dig and prepare the site.  Decide on the shape of the pond by using a garden hose or rope to test various outlines on the ground.  When locating the outer perimeter of the hole, do not forget to consider the thickness of the plastic or concrete liner.  A concrete lining may add about four inches to the diameter of the hole.  

The next step is to outline the shape of the pond with spray paint so that your design will not be lost during excavation.  Once this is done, it is time to start digging.  Remove the soil to the desired depth and slope the sides to about a 45 degree angle if you will be using concrete.  Make sure that you dig a shelf for edge plants and do not forget to compact the earth on the bottom and sides of the hole. 

You will want the water in the pond to be level within the garden so it is essential to make sure the top edges of the pond are level during construction.  Check the edges of the hole regularly with a carpenter’s level in several directions to ensure proper orientation .  If you include a pump and fountain, decide where to place the electrical cord and water-return line at this time.

The next step is to install the liner.  If a plastic liner is to be used, simply place the liner into position and gradually fill in around the edges of the liner with soil.  It is a good idea to begin filling the pond liner with water at the same time to make sure that the pressure of the soil does not cave in the liner before backfilling is completed.  

A concrete liner will require the placement of a wire mesh within the concrete for strength.  Mix the concrete into a fairly stiff, not runny, mixture and place the concrete into position with trowels.  For difficult nooks and corners, it may be necessary to use your hands so have a pair of rubber gloves handy.  Once the concrete is in place and smoothed, wet the concrete often with water to slow the drying process and help prevent cracks that would later allow water to escape from the pond.

Finally, the last step is to install the features and plants that will make your pond into a garden.  Waterfalls and fountains will require small pumps and tubing to remove the water from the pond and release it again at the appropriate place.  Water lilies and other plants will provide greenery and colorful flowers to the garden.  Fish, such as goldfish, will add diversity and turn your pond into a small ecosystem.  

One final piece of advice may be helpful. To prevent your pond from becoming a mosquito haven, add a school of small mosquito fish.  Their voracious appetites for mosquito larvae help break the insect’s life cycle, and keep your yard free, of these annoying and potentially disease-transmitting pests.

A water garden can make an attractive addition to any landscape.  They provide color, interest and a unique feel to an outdoor living area. With a little time, a few resources and some know-how, anyone can build, maintain and enjoy a soothing and refreshing pond or pool.

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