Landscape Design

Low Water Use Gardening for Sedona and the Verde Valley

by Brian Lane

Along with food and air, water is one of the most basic, sustaining elements of life as we know it. As the Verde Valley has grown, this precious resource has become stretched to its capacity, becoming the top issue of concerned area residents. Studies show that nearly half of all water use in urban areas is for lawn and garden purposes. To have the ability to sustain ourselves here in this beautiful environment, we all must help in the effort to conserve water. Low water use landscaping, or xeriscaping (pronounced ZIR-i-scaping), presents an opportunity for us all to become better stewards of this life-giving liquid. The benefits of reduced landscape watering include positive environmental impact, economic savings, reduced maintenance requirements, and overall visual enhancement in harmony with natural surroundings.

Efficient Planning and Design

Start with an overhead sketch of the area. Try to note important existing conditions such as drainage, sun and shade areas, existing plants, unusual soil conditions, unusual slopes, unsightly views that you would like to screen, and the good views you want to frame. Think too about the activities that you plan in your outdoor areas, and plan accordingly to provide the proper shade, shelter, screening and spatial delineation between these areas.

Basic principles of composition are:

Simplicity. The careful arrangement of a few species is more pleasing and creates a sense of unity over using a collection of many different plants.
Scale. Use smaller plants in smaller spaces and larger plants in open areas or near tall, bare walls.
Balance. Arrange plants informally to create a natural-looking balance. Stagger the plantings and use an odd number of plants (three, five or seven), keeping them in groups.
Sequence. Use the form, color, and texture of your plants to create a sense of rhythm and balance.
Focus. Locate focal points around which other masses of plants can be arranged.

Limiting the Area and Type of Turf

If you must have a manicured lawn, limit the area to no more than 500 square feet (or about 20’ x 30’), and use perennial rye, Bermuda or Fescue grasses in lieu of Bluegrass varieties. Consider using the more drought-tolerant alternative lawn grasses such as Buffalo grass, Blue Grama, or Sheep Fescue, or eliminate the lawn altogether and use ground-cover plants like Verbena, Mexican Primrose, or Ice Plant.

Efficient Irrigation

Drip irrigation systems with automatic timers should be used to water your landscape plants. Make sure to group plants with the same water requirements together on one water line, or zone. Understand that trees, turf, and bedding plants all have very different watering needs.

The landscape should be watered early in the morning, just before sunrise. It gives the water a chance to soak in before the sun begins its drying effects, and ensures that less evaporation occurs than when watering during daylight hours. Lawns that stay wet overnight are more susceptible to fungus; when mushrooms begin to appear, you know that the lawn is staying too wet. Also, if using popup-style lawn sprinklers, keep the lawn grass from interfering with their operation, and check the pressure at which they operate. If they are misting, you are losing a large percentage of your water through drift and evaporation. Consider using a pressure reduction device or adjusting the spray, if possible.

Soil Improvements and Mulches

Well-composted manures and mulches can be mixed with native soil to improve overall composition. Composted mulches should be spread 2-3” thick on top of the bare soil, under your plants. They help retain moisture, reduce soil compaction, reduce weeds, and add organic matter to the soil. Be careful not to push mulch against the stems of vegetables, perennials, or bedding plants, as it tends to stunt their growth.

Use of Low Water Use Plants

It should go without saying that only plants requiring a minimal amount of supplemental irrigation should be employed in the Southwest landscape. Native plants are ideally suited for use in the landscape, but be aware that some, especially taller shade trees, will not survive without supplemental irrigation.

Appropriate Maintenance

Be sure to make proper seasonal adjustments to the timing of your irrigation. During winter months, root systems still need moisture if there is little natural precipitation, and you may want to run the system during the day after lines have thawed. Aerating and dethatching of lawns is another great way to make sure water penetrates deeply into lawns and to avoid excess runoff. Remember too that as trees and shrubs grow, they increase in irrigation needs and should be provided deep, widely-spaced irrigation. The outside edge of the tree canopy is called the drip line, and this is the optimal area to set drip emitters.

Getting Drought-Tolerant Plants Established

Remember when purchasing plants that smaller container plants are easier to handle, more successfully transplanted, less expensive, and usually catch up to the height of larger container plants that are planted at the same time.

After purchasing your plants, try to keep them shaded and water them daily until you are ready to plant. Dig the hole twice the width of the container and only as deep as necessary, in order to match the top of the rootball to the level of the surrounding soil. The majority of plants that struggle or die do so because they have been planted too deeply. It is always better to plant them a little high than too deep.

Remove the plant from its container, being careful not to wrench it out, as you could easily rip the feeder roots from the plant. It's better to turn the container upside down, or on its side, in the case of heavy or tall plants, and slide the plant out. Cut the plastic container if necessary.

Amend the soil with a little composted mulch and bone meal, mixing it thoroughly with native soil. Backfill the rootball slowly, making sure to leave no air pockets in the soil. You can compact the backfilled soil, but use caution not to push down on the rootball. Build a circular soil dam around the plant to help retain moisture, and water thoroughly.

You’ll want to water once a day for the first three weeks and then every other day for the next few weeks. The next step is to water deeply two times a week for a month, once a week for the next month, then twice a month for a few months or until frost. Once the plant is established, only occasional watering is necessary during dry spells. Slow, deep, infrequent irrigation should be the rule.

Other Conservation Tips

For energy savings, try planting taller deciduous trees on the south and west sides of the house. You’ll enjoy the shade during the summer heat and when the leaves drop for winter, the sun will shine through and you can enjoy its warming rays.

If a plant is suffering from drought, do not keep it soaked for the next few days, as so many want to do. It tends to compound the problem, as the dry plant now suffers from oxygen deprivation by keeping all the air pores in the soil clogged with water.

Non-native plants such as annual color plantings that require more water should be located closer to the house, while more drought-tolerant natives can be used to naturalize the landscape into its surroundings.

Although native varieties will need extra water while they establish their roots and during a prolonged drought, you should remember that watering need only occur occasionally, with a long, slow drip. Never water your landscape cactus, although ocotillo (or coach-whip) can benefit from occasionally misting the canes.

Plastic should NOT be used to keep weeds from the landscape. It doesn’t allow the soil to breathe or roots to grow, and effectively sterilizes the soil. Plus, when we do get rain, it can cause excessive water runoff. If you must use a weed suppression fabric, it should be a woven polypropylene-type material (although when it is covered with granite stone, you’ll find that weeds grow on top of it). Better yet, just spread the stone about 5”-6” thick to shade out the sun from the soil, and hand-pick the few weeds that come up.

The best time of year to plant most trees, shrubs, or hardy perennials is later in the fall, winter, and very early spring. Try never to be planting in the heat of summer, as it will require substantially more moisture to get the plantings established. If you must plant in the heat, dusk is the best time of day to avoid heat stress to the plant.

Recommended Native Plants

Trees:

Desert Willow (Chilopsis linearis)
One-Seed Juniper (Juniperis monosperma)
Alligator Juniper (Juniperus deppeana)
Utah Juniper (Juniperus osteosperma)
Pinon Pine (Pinus edulis)
Arizona Sycamore (Platanus wrightii)
Arizona Ash (Fraxinus velutina)
Arizona Cypress (Cupressus arizonica)
Arizona Mesquite (Prosopis velutina)

Shrubs:

Creosote Bush (Larrea tridentata)
Four–Wing Saltbush (Atriplex canescens)
Desert Broom (Baccharis sarothroides)
Buffalo Berry (Sheperdia rotundifolia)
Apache Plume (Fallugia paradoxa)
Beargrass (Nolina microcarpa)
Mountain Mahogany (Cercocarpus montanus)
Curl-Leaf Mahogany (Cercocarpus ledifolius)
Smooth Sumac (Rhus glabra)
Sugar Sumac (Rhus ovata)
Rabbitbrush (Chrysothamnus nauseosus)
Squawbush (Rhus trilobata)
Mockorange (Philadelphus microphyllus)
Manzanita (Arctostaphylos pungens)
Mormon Tea (Ephedra viridis)
New Mexico Locust (Robinia neomexicana)
Cliffrose (Cowania mexicana)
Fernbush (Chamaebatiaria millefolium)
Desert Ceanothus (Ceanothus greggii)
Chokecherry (Prunus virginiana)
Red Twig Dogwood (Cornus stolonifera)
Elderberry (Sambucus glauca)
Soaptree Yucca (Yucca elata)
Banana Yucca (Yucca baccata)
Spoon Plant (Dasylirion wheeleri)

Perennials:

Evening Primrose (Oenothera hookeri)
Scarlet Buglar (Penstemon barbatus)
Sulfer Eriogonium (Eriogonium umbellatum)
Sacred Datura (Datura meteloides)
Shooting Star (Dodecatheon pulchellum)
Blue Flax (Linum lewisii)
Yarrow (Achillea millefolium)
Desert Marigold (Baileya multiradiata)
Skyrocket Gilia (Gilia aggregata)
Arizona Lupine (Lupinus arizonicus)

Cactus and Succulents:

Hedgehog Cactus (Echinocereus var.)
Century Plant (Agave var.)
Ocotillo (Fouquieria splendens)

Please note that some plants on this list may not be commercially available at all times, but all have been found recently, either locally or via mail-order. Also, there are many drought-tolerant plants that work well in the Verde Valley but are not considered native, and therefore have not been included on this limited list.

One final rule of thumb when searching for effective drought tolerance is to make note of a plant's leaf size. Larger leaves transpire (give off water vapor through the leaves) more than smaller-leaved plants.

Sources for Drought-Tolerant Native Plants

Please check your local telephone directory under ‘Nurseries’ to find the phone number and location of a nursery near you. Two excellent Internet / mail order sources are:

Plants of the Southwest
3095 Agua Fria
Santa Fe, NM 87507
(800) 788-7333
www.plantsofthesouthwest.com

High Country Gardens
2902 Rufina Street
Santa Fe, NM 87507
(800) 925-9387
www.highcountrygardens.com

About the author:

Born and raised in North Brookfield, Massachusetts, Brian has lived in Sedona for nearly fifteen years. An artist, writer, and paralegal studying to facilitate court mediations, he lives with his wife La Quita on a small ranch in the Red Rock Loop area. A certified horticulturist and avid hiker and backpacker, Brian is currently president of the North Central Arizona Regional Watershed Consortium, secretary for Sustainable Arizona, and a member of the Interim Planning Committee for the Verde River Basin Partnership. You can e-mail Brian at hikernut@commspeed.net.

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Keep Sedona Beautiful promotes conservation of the greater Sedona area, and, by all practical means, seeks to preserve the unique natural environment and to enhance the quality of life for future generations.

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