PLANT LISTS |Selecting Plants| Drip |Drought Landscape Tips | How To Plant | Tree Roots |Pruning | Soil Probe | Turf Removal | Water Harvesting | Watering Schedule | Watering Trees and Shrubs| Watering Turf | Weed Control | Publications

Landscaping

Xeriscape:

Landscaping with Style in the Arizona Desert -

an on-line version of a step-by-step landscape installation guide

Xeriscape Overview:

Water efficient landscapes can be used anywhere - from small residential yards to large commercial sites. They can also be the most water wasting. Water use in landscaping can account for up to 50% of a typical family's water bill. Here are some tips to help you have a beautiful landscape yet be water efficient:

The Water Wise program promotes a landscape technique called "Xeriscape™. Xeriscape is a term a group of water professionals created in 1981. It is derived from two words: xeros or dry, and scape as in landscape. All put together, it means "low water landscaping". But remember! There isn't any "zero" in xeriscape!

Xeriscape can be colorful, exciting and water efficient. Here are seven general principles:

1. Design: Plan your landscape to include what you want and don't want. The more thought you and your family put into the landscape BEFORE it is installed, will mean less work for you later. Make a "Wish List". Ask yourselves questions, for example: Will you be entertaining? What size group? What views do you want hidden? Enhanced? Where would the kids like to play? Will there be a garden? Do you want to attract wildlife for watching? What do you want from your landscape in the future? What can you afford? In designing a xeriscape, think zones.
   
   Zones: It is helpful to divide your yard up into water use zones:
   
• "Mini Oasis". This is the area immediately around your house. It can be the patio area, the area outside your front door, a courtyard. By planting this area with moderate water using plants, you will help to cool your house. You can use the water that falls off your house and hard surfaces to supplement irrigation. Pay special attention to the west exposure of your house. This is the side that can get very hot in the summer, and could benefit from the shade of a tree. The south side will not get direct sun in the summer, but will be warmer due to reflected heat. This would be the place to have low plants, groundcover, or if you need it, a small patch of turf. In the winter, the south side of your house will benefit from the sun as it's angle is lower in the sky, so you don't want to plant a tree here as it will shade your home in the winter. The east side of a house is a wonderful place to plant just about anything as plants appreciate morning sun and respite from the hot afternoon southwestern sun. North  facing exposures are predominately shady, and don't need plants, but if that part of your house is visible, you will want to use more shade tolerant plants.
• "Transition Zone": This is the area just outside of your mini oasis. It is an area for plants that need some irrigation. You can use mounding and contouring techniques to direct rainwater to the planted areas as well as micro-basins to catch run-off for use by trees and shrubs. Choose low water using plants for this area.
• "Desert or Natural Zone":  Here, you can either let the natural vegetation provide habitat for wildlife, or you can enhance the natural surroundings by using drought adapted native plants. The emphasis here is to have plants that can survive on rainfall alone. You will also want to use the rainwater harvesting techniques mentioned for the transition zone.
• Don't forget that you will need to give your plants in each zone special attention for the first 1-3 years while they get established, even if they are native, low water use plants.
2. Appropriate Turf Areas. Turf is the highest water use landscape component. It is also the most labor intensive. If you have moved to the Southwest from a  more temperate climate where grass grew easily and needed little attention, recognize that turf in the southwest takes more care. Ask yourself if you need turf, or how much and where you will use it. Choose a turf grass carefully, as there are warm season grasses like a native Buffalo grass that only grows to a 4" height and needs little fertilizer, or a cool season grass like tall fescue that can be pushed to stay green over the summer by giving it extra water and fertilizer. You may also wish to remove your turf.
3. Plant Selection. Choosing the right plant for the right place makes your landscape maintenance job either pruning and watering all weekend, or swaying in a hammock sipping a cool drink and watching the butterflies. Group similar water use plants together for easy watering. Know the mature dimensions of the plant before you plant it, what conditions it likes to grow in, if it drops litter and if that will be a problem where you want to put it. Don't forget to look up before you plant. There just may be a power line below the mature height of that pine you wanted! Read plant tags, talk to local nurseries, your Cooperative Extension, go for walks in the the natural areas around your house and research landscape books to learn about your plant choices.
4. Soil Improvements. Desert soils have little organic material in them and are basic in pH. Desert plants have adapted to grow in these poor soils. Adding organic material to gardens and  turf areas is appropriate, but not for many low water use landscape plants- they just don't need it!
5. Mulch, Mulch, Mulch! This is where you can put all that organic material you wanted to put in the soil! Three inches on top of the soil in your landscaped area will help keep the moisture in the ground by greatly reducing the evaporation rate, and helping to suppress weeds. The mulch material can be inorganic (rock) or organic. Shredded bark makes a good mulch as it tends to knit itself together and be less likely to float or blow away. The organic material will decompose and water will take some of the nutrients to the plant's roots. In many places rock is appropriate, and neutral colors like beige and light browns are cool and non- reflective.
   
   Weeds: Do not use black plastic as a weed control. Plastic runs rainwater off of your property, traps moisture underneath it causing plant roots to grow near or on top of the surface and oxygen cannot get to the soil. It also may mean more erosion from water in your neighborhood drainage channels or excess water in the sewers. For good weed control, prepare your area by killing all unwanted plants putting down a 2 in. - 3 in. depth of rock or an organic mulch, and using a pre-emergent. For about the first three years more weed control will be needed than in the future, as the weed seeds had been disturbed and grew! Weed fabric is another option for weed control. It is a porous cloth that is placed on the soil with rock or mulch on top of it. The porous nature allows water and oxygen to penetrate. This material is available in garden stores. (For more information on weed control, see "turf removal").
6. Irrigation. One of the greatest wastes of water is watering too much, too often. Putting just the right amount of water in the right place for your plants is both healthy for them and easier on you and your water bill. There are several ways to do this:
• "Catch Rain, Dear" Water harvesting is the easiest, best and cheapest way to water plants. Rainwater doesn't have the mineral content of groundwater and won't burn your plants. However rain comes sporadically and can be used to supplement irrigation for oasis and transition zone plants but can be the sole water source for desert zone plants.
• Catching rain is simple. Build some gentle packed earth ridges (6 in. or higher) perpendicular to the flow of water (or on contour) either on the uphill or downhill side of a plant at the dripline. If you are preparing an unplanted area, dig to have a trench and a berm. Digging trenches near mature plants can cut into their root systems, causing injury .
• Areas that have poor drainage can benefit from digging a deep hole (2 or so feet deep) preferably past the poor draining material (clays, limestone, etc). Fill the hole with gravel and top dress it as is the rest of the landscape. A tree or shrub can be planted on the edge of this lower depression to use the water held in the area.
• Dry washes can be created to move water through a landscape and control overflow. Sinuous washes with irregular sized rocks help to slow the flow of water as it moves through the area. Keep in mind that your goal is to keep water on your property.
• Storage of rainwater can be as small as a bucket or as big as a tank. Barrels, horse troughs, empty swimming pools and water gardens all can store water for use in the dry seasons. Covering the surfaces and using mosquito control products will help keep the water clean and safe for plants.
• Drip Drip irrigation is a system of plastic tubing that delivers water to a plant landscape. It is designed to slowly deliver water to the plants root system allowing the water to soak in rather than run off or be evaporated by wind or sun. The specific delivery of drip makes it an efficient way to water landscapes- if managed properly.
• Good systems will have different valves or stations for the different water needs of plant. Trees, shrubs, bedding plants and turf all had different water needs. Trees roots are found in the top 3 feet of soil. Each time a tree is watered, the water should soak from the top of the soil to a depth of 3 feet. Shrub roots are about 2 feet deep, and bedding plants and turf roots are about 1 foot deep. So you don't over or underwater your plants - remember it's as easy as 1-2-3.
• How deep water penetrates can easily be determined by using a soil probe. This is a a thin metal rod (3/8 in. or so) about 2'-3' long. Irrigation turn-key's can be modified into soil probes by cutting of the "u" at the end. Insert the probe into the ground after about an hour after watering. It will stop when it reaches dry soil. If a rock is hit, try another place. Look at the end of the rod and check for moisture. When the rod won't penetrate the soil more than 4 in., then it is time to irrigate deeply again.
• Deliver water at the drip line of a plant. This is the area directly underneath the outer tip of the branches. This is where roots can best absorb water. When it rains, the foliage of the plant keeps water from landing underneath it, but drips water off the ends of the branches for the tips of the roots to absorb. Expand your irrigation emitters as your plant grows.
• Once you become familiar with your system and how your plants use water, then you can determine watering schedules for the four seasons and program them into the controller.
• Enormous waste occurs in neglected irrigation systems. Broken lines, misplaced emitters, poorly designed systems all add up. When an irrigation system is installed, a plan should be made and kept with house papers for referral- for you and future owners. Use the plan to check emitter placement, output, and general maintenance at least once a year.
• Micro-Basin Flooding: With this method of irrigation, berms are used to contain water delivered at a faster rate than drip. A single bubbler is put near the base of the plant or series of plants, and the entire root system is flooded. Berms need to be expanded as the plant's dripline expands. When bubblers are designed into a system, they should always be the method of irrigation as the plant roots grow to absorb water delivered in that way. Bubblers should be placed far enough away from the base of the plant as to not promote root rot from contact with wet soil. Use the soil probe method for determining how long to run your system for optimum water use. Keep in mind that water has weight. As weight is put on soil, and the soil becomes compacted, less pore space is available for water, and the soil may not be able to absorb as much water as it used to.This is a disadvantage to basin-flooding as a watering method.
• Soaker Hoses: These hoses are black porous hoses generally made out of recycled rubber. When screwed on to a regular hose, the soakers "weep" and deliver water at a slow rate. Soaker hoses can be used to temporarily water desert zone plants if the season has been particularly dry, or be put in flower beds. Cover them with mulch and they can be left unnoticed.
• Hand - Held Hoses/Manual Sprinklers: Outdoor faucets can flow as much as 5 gallons a minute or 300 gallons per hour. Often sprinklers and hoses deliver water at a much faster rate than the soil can absorb. Excess water often runs-off and doesn't have a chance to soak into the soil, potentially wasting a lot of water.
7. Maintenance. A stitch in time saves nine. Knowing how your landscape functions and keeping up on repairs, catching weeds before they set seed and adjustments to the water systems and schedules will save you hours of labor. Xeriscapes are designed to require minimal care. However, you might find yourself puttering around the yard, just because it is so easy and beautiful.

Fun Facts

• Sierra Vista Sub-Basin: This is the watershed that is bordered by the Huachuca and Mule mountains in Arizona. It includes the towns of Bisbee, Palominas, Hereford, Sierra Vista, Huachuca City, and Whetstone. Presently the population is using more groundwater than is being naturally replenished and the aquifer is in "overdraft". The residents of the Sierra Vista Sub-Basin depend solely on groundwater as their water source.
• Annual Precipitation: The annual precipitation rate for the Sierra Vista Sub Basin is about 15 inches of water per year.
• Average Low Temperatures: The plant hardiness recommended for this sub-basin is 15 degrees Fahrenheit.
• Evaporation Rate: 5 feet per year from a body of water in the Sierra Vista Sub Basin can be lost to evaporation. This means that more water evaporates than the sub basin receives from natural precipitation. This is why a mulch on top of the ground over plant's root zone is so important.
• Evapotranspiration Rate: This is the evaporation rate and the moisture lost from a plant (transpiration) combined.