B E T T E R   L A N D S C A P E   D E S I G N

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Landscaping Responsibly

by Sandy Turico,
Master Gardener

We see it in the newspaper headlines and hear it on the evening news...severe drought conditions, groundwater and soil contamination, rising levels of pollutants. As if that isn't troublesome enough our natural resources are in jeopardy; explosive population growth in Maricopa County along with the lack of substantial precipitation has many wondering how long we will have an adequate supply of water.

That's the bad news...the good news is that the manner in which we design and maintain our home landscapes can make a significant difference.

Establishing and maintaining a verdant landscape in the desert and being environmentally responsible can go hand in hand. Developing an earth-friendly plan, choosing appropriate plants, irrigating efficiently, and limiting fertilizer and chemical use are the keys to responsible landscaping.

THE PLAN
Whether landscaping a new home, renovating your current landscape or making minor changes in your yard, develop a design that will have a minimum impact on the environment. Think carefully about how you use your yard. Be creative in finding ways to limit your water use.

Hardscape features such as patios, fireplaces and pathways can make your landscape more livable-and they don't need to be watered!

Maintaining a lawn requires a tremendous amount of water and fertilizer. Some will argue that a lawn is necessary for those with small children or pets. If you must have one, consider limiting its size and make certain your sprinklers are directed at the lawn so you aren't irrigating your patio or sidewalk.

Pools are high priority items in our hot desert climate, but they involve using a considerable quantity of water and chemicals. A pool cover minimizes water evaporation and chemical requirements. If you love the idea of having a water feature in your yard, there are many attractive alternatives such as fountains and ponds.

Plan for a "mini-oasis" if you love growing roses or other plants with high water requirements. Plant them near patios and seating areas where you can enjoy them.

THE PLANTS
Select native and desert-adapted vegetation. These plants have evolved in ways that allow them to thrive in our arid climate. Small, narrow leaves, light green or gray foliage, and other leaf modifications are just a few ways that these unique plants conserve moisture. They survive in their natural habitat with little water and low humidity, and they tolerate the alkalinity present in the desert soil.

Take time to learn about the plants available in our area. Visit your local botanical garden, attend landscape classes, get on the Internet, and take advantage of the resources at your Cooperative Extension office or local library. Low-water plants are available in every size shape and color imaginable. Look around and you're sure to find some favorites.

Layer your plantings. Use trees, shrubs and groundcovers in your plan. Many smaller shrubs and groundcovers will benefit from the shade provided by larger plants and trees.

Consider using plants to shade some of your paved areas. Paving materials absorb then release heat, which can increase the water requirements of nearby plantings.

Don't plant more than you can care for. It's tempting to stroll through a nursery and fall in love with every plant you see, but if you don't have time to properly maintain your landscape, you will waste water and energy.

IRRIGATION
It is estimated that over 60 percent of the water used by the average homeowner goes for landscape irrigation. Conserving water does not mean resigning yourself to a yard full of rocks, boulders and a few cacti. A flourishing landscape is attainable with careful planning.

• Irrigation equipment
  Watering your landscape can be accomplished through flood irrigation, sprinklers, bubblers, or drip irrigation. A drip system is a very practical method to keep your plantings in tiptop shape. Since water is applied exactly where it is needed in a slow trickle, evaporation and runoff are greatly reduced.
  
  Using an automatic control box to regulate your irrigation is an efficient way to get the job done. Adjust your watering schedule seasonally. Duration of the irrigation should not change, only the interval between irrigations.
  
  Group plants with similar water requirements into separate zones in your system.
  
  No matter what type of irrigation you use, remember to check it periodically. Look for leaks in the system, broken sprinkler heads and plugged emitters.



• Watering schedule
  Knowing when and how long to irrigate is not an exact science. Water applied deeply and infrequently to the entire root zone will result in stronger, healthier plants capable of withstanding our searing summer heat. A consequence of irrigating too frequently is weak roots that are unable to absorb nutrients.
  
  Water trees to a depth of 36 inches; shrubs to 24 inches; groundcovers, cacti, and annuals to 12 inches; and lawns to 10 inches. Use a soil probe to determine how deep the water is penetrating. The type of soil you have determines how fast water is absorbed and how far it spreads.
  
  More plants suffer from overwatering than under-watering. Indications of water stress are wilted, curled, or drooping foliage; yellowed older leaves that drop; and dead stems or branches. Symptoms of excess irrigation include brittle leaves that remain on the plant; wilted shoots; soft, smelly tissue; and algae or mushrooms present in the area.
  
  Mulching your landscape plants will decrease the amount of water needed to sustain them. Three to four inches of rock mulch or organic mulch such as compost, leaves, grass clippings, branches, or pine needles will cool the soil, reducing water loss from evaporation and limiting the growth of weeds that compete for water. Using organic mulch has the added benefit of improving soil structure.

FERTILIZERS
Using native plants will greatly reduce or eliminate the need for fertilizers. The desert produces little organic matter, and these plants have survived in the wild without soil amendments for eons. A minimum amount of fertilizer can be used to give the landscape a boost, but is not usually necessary.

The foliage color of plants is not necessarily indicative of the need for fertilizer. Plant diseases, insects and weather conditions can cause abnormal leaf color. Use a soil-testing kit when you are in doubt.

Too much fertilizer will stimulate excessive growth and promote the occurrence of disease and pest damage. Overgrowth leads to pruning, which adds unnecessary yard waste to our landfills.

A plant cannot tell the difference between organic and synthetic fertilizers. However, organic fertilizers such as manure, compost, fish emulsion, and bone meal are slow release, lasting over a longer period of time. They are less apt to burn plants and can actually improve soil conditions.

CHEMICAL USE
By definition, pesticides include insecticides as well as herbicides. While it is sometimes necessary to resort to chemical use, it is easy to become dependent on them. The inherent danger in the overuse and inappropriate application of pesticides is the poisoning of our natural resources and possible disruption in the balance that normally exists in nature. Decide how severe a problem is and how much damage you are willing to tolerate. Use chemicals as a last resort.

Read the labels...they're there for a reason! Chemicals are toxic. Safe use depends on following the directions and heeding the precautions on the label. Apply the correct amounts...more is definitely not better.

Minimize insecticide "drift" by applying the chemicals on a windless day.

Store chemicals in a cool, dry, well-ventilated place. It is imperative that these toxic materials are locked away from children and pets.

Always keep chemicals in their original, labeled containers.

Make sure bags or containers are not damaged or leaking.

• Insecticides
  Follow Integrated Pest Management or IPM guidelines. Monitor the affected plant to determine what type of damage is being done. Verify that it is an insect causing the problem and identify the pest. Decide if any action is necessary. If you choose to correct the problem, use the least toxic solution possible.
  
  According to the Master Gardener manual, "We generally associate insects with crop loss or disease transmission, but only a small number of insect species (less than 3 percent) are considered to be pests of humans, animals, crops, or fiber. Most insects are either outwardly beneficial or harmless." Therefore, the sensible solution is to control pests without harming other insects.
  
  Non-toxic solutions include mechanical traps and barriers, water and soap sprays, and removing and destroying large insects by hand. Home remedies such as hot peppers, garlic and herbal mixtures may be helpful.
  
  Another option is biological controls...predators, parasites, and diseases.
  
  
• Herbicides
  Herbicides kill vegetation-both landscape plants and weeds-so utilize these chemicals with caution.
  
  Hand pulling or hoeing weeds is a tedious yet effective means of control. Make sure you remove the weeds before they go to seed.
  
  Boiling water and vinegar sprays are home remedies worth trying.
  
  Never use soil sterilants in a landscape setting. In addition to eliminating plant growth, they remain in the soil for long periods of time and may spread through the soil and kill desirable plants.

Landscaping responsibly should be a top priority for the homeowner. Show your appreciation for our beautiful desert environment by protecting it!

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"On every stem, on every leaf, ...and at the root of everything that grew, was a professional specialist in the shape of grub, caterpillar, aphis, or other expert, whose business it was to devour that particular part." --Oliver Wendell Holmes

Photos courtesy of Candice Sherrill


Maricopa County Master Gardener Volunteer Information
Last Updated May 28, 2003
Author: Lucy K. Bradley, Extension Agent Urban Horticulture, University of Arizona Cooperative Extension, Maricopa County
© 1997 The University of Arizona, College of Agriculture and Life Sciences, Cooperative Extension in Maricopa County
Comments to Maricopa-hort@ag.arizona.edu 4341 E. Broadway Road, Phoenix, AZ 85040,
Voice: (602) 470-8086 ext. 301, Fax (602) 470-8092