You can improve the look of your landscape and save water by replacing some of the high water plants in your yard, such as grass, with low water plants that are adapted to your climate. Selecting trees, shrubs and other plants that are adapted to your local conditions will grow better, generally require less maintenance and use fewer inputs such as water, fertilizers and pesticides. The information below will help you incorporate more water-wise plants into your existing landscape.
Modifying Your Landscape
You probably already have a landscape with a variety of low, medium and high water using plants. This doesn’t mean you need to remove all the high or medium water using plants. Before you change out any existing vegetation on your property:
- Investigate the water needs of your existing plants.
- Determine whether your existing plants are grouped according to their water needs and relocate or remove plants that are incompatible with each other.
- Irrigate efficiently by maintaining your system and applying the appropriate amount of water.
- Apply a 3-inch layer of mulch or compost around plants to reduce evaporation, promote plant growth and reduce weeds.
After this you may wish to modify your landscape to incorporate more water-wise plants. Grass is usually the thirstiest part of the landscape, so unless you use your lawn on a regular basis, consider reducing it in size. First decide how you would like to modify your landscape. Perhaps you would like to create new planting beds of perennials or flowering shrubs; or maybe you would like to incorporate a patio or garden paths into your landscape. Before you begin it’s a good idea to review STEP 1 Design a New Water-Smart Landscape and sketch a design for your landscape modification. These design tips will help:
- Plant trees, shrubs and other perennials in beds and group them according to their water and sun exposure needs (see Hydrozones). Avoid planting trees and shrubs in your lawn.
- Provide adequate width for bed and border planting areas – A generous width will give plants spreading room, reducing maintenance and keeping the plant’s natural shape.
- Perennials and small shrubs should be planted in beds at least 4-feet wide.
- Taller shrubs and hedges should be planted in beds at least 6-8-feet wide.
- Use porous materials for building patios and walkways so that rain soaks into the ground rather than running off. Flagstone and pavers set in sand or gravel for paths are good choices. (You can underlay these materials with landscape fabric to prevent weeds from sprouting.)
- Avoid leaving turf in narrow strips or oddly shaped areas when reducing lawn size because they are difficult to irrigate.
- If you have an automatic sprinkler system with several irrigation zones, convert an entire zone at a time. A mixed zone with both lawn and low water using plants can not be irrigated correctly.
Selecting water-wise plants
Landscaping with water-wise plants (often referred to as “Xeriscaping”) has become popular in recent years. Water-wise plants are adapted to local conditions and, therefore, generally grow better, require less maintenance and use fewer inputs such as water, fertilizers and pesticides. Water-wise plants develop extensive root systems to effectively gather water and are more drought tolerant. Keep in mind that all new plantings take time to establish, and will need regular watering for first few years.
There are a wide variety of colorful, fragrant, and beautiful plants that require minimal irrigation. Many have long blooming seasons and attractive foliage. Some provide autumn interest with colorful foliage and fruit, while others offer winter interest with their fruit, seed stalks, and winter colors ranging from silver, to gray, to many different green and brown shades.
The key to successful water-wise landscaping is selecting plants that are adapted to your local climate and site conditions. When choosing plants consider the following factors:
- Climate – the trees, shrubs and other plants you select should be adapted to withstand the temperature and other climatic extremes in your region. Determine your climate zone by going to the U.S. Department of Agriculture climate zone map at Plant Hardiness Zone Map www.usna.usda.gov/Hardzone/ushzmap.html. For the western U.S., use the more detailed Sunset climate zones map found in the Sunset Western Garden Book www.sunset.com.
- Microclimate – consider the microclimates of your yard, such as sun or wind exposure and then select the appropriate plant for the appropriate place in your landscape. The orientation of your house, other structures and large shade trees will all affect the microclimate of various locations in your yard. Sun loving plants will prefer southwestern exposure. Shade loving plants or ones that prefer cooler climes will prefer a northern exposure.
- Water needs – choose medium or low water using plants adapted to your climate and then group them in your landscape design according to their water needs so they can be irrigated efficiently. Select low water using perennial plants instead of annuals, which have to be re-planted every year and generally require more maintenance and water.
- Soil – consider the soil preference of the plants you select. Some plans thrive in well drained sandy soils others in more organic or clayey soils. If in doubt, have your soil tested.
- Placement in the Landscape – know the mature size of the plants you select and make sure there is adequate space for them in your design when they are fully grown.
After you have considered these factors, use the Plant Search function in the Garden Gallery to help you select beautiful water-wise plants adapted to your specific climate and site conditions. Basic information is provided on a wide array of plants, including soil and climate preference, water needs and growth habits. Photos allow you to select plants based on aesthetic considerations such as foliage, plant shape, flower color, etc. Your local nursery or university cooperative extension is also great resource for information on locally adapted plants.
For more thorough information on selecting water wise plants see STEP 2: Choose the right plants.
Deciding on Irrigation
Before planting, decide on how you will water the new plants. Even water-wise plants will require watering for the first year or two until their roots are established. You can either water by hand or install a drip-irrigation system. If you water by hand, a watering wand with a shut-off valve in the handle is a good choice. Another “semi-automatic” option is to attach an inexpensive timer valve to your outside faucet and then run a soaker hose or drip irrigation under the mulch of the newly planted bed. Set the timer to apply 1 inch of water 2-3 times per week according to your climate and plant materials. If soil is wet to a depth of 6 inches, do not apply additional water until it dries out. Otherwise the plants may drown or rot.
If you plan to use an automatic irrigation system, drip systems are much more efficient than overhead systems for irrigating trees, shrubs and planting beds. You may already have a sprinkler system with pop-up heads in the area that you are converting to a water-wise garden. Fortunately, it is fairly easily to convert an overhead system to an efficient drip system. New drip adapter heads are now available that screw into an existing pop-up head. See Drip Irrigation for more information.
Planting the New Bed
The best time to plant a new landscape bed is late fall or early spring. The soil is generally easier to work this time of year, and this allows the new plants some time to become established before the onset of hot summer weather.
STEP 1: Outline the contour of the new planting bed (a garden hose works well for this). Then use a spade shovel to cut the contour of the bed. If you are reclaiming a stretch of lawn for a garden bed, begin removing the turf by working the spade 2-3 inches below the surface of the sod, shaving off manageable pieces. (The sod can be piled somewhere in your yard to make excellent compost/topsoil). If this method sounds like too much work, you can cover the area with clear plastic to kill the grass. Allow at least four weeks for the black plastic or herbicide to work.
STEP 2: Use a regular shovel or a roto-tiller to turn over the soil to a depth of 8-10 inches. It’s a good idea to have your soil tested to see what types of plants will grow best or if it needs amending. If the soil is too sandy or too clayey, apply a 3 inch layer of compost to the planting bed and dig it in thoroughly. This will improve the soil’s texture and ability to hold moisture. After the bed is prepared, you may wish to lay down a permeable landscape fabric over the planting bed to suppress weeds (never use an impermeable material such as black plastic).
STEP 3: Water your new plants a day or so before planting them to make sure the roots are moist. Position the plants in the new bed according to your plan. Reposition as necessary, until you get the desired look. Remember to allow ample space between plants based on the plant’s fully grown size. Taller plants should be not shade out sun loving plants or block them from view. Dig each planting hole twice as wide, but no deeper than the potted plant (or root ball). Slide the plant out of its container and inspect the roots. If they are pot bound (i.e. over grown) prune back all the twisted roots so they will have fresh start. Place the plant in the hole and back fill with the excavated soil (amended soil or potting soil is not recommended). Tamp the soil around the plant up to the level of the existing root ball. Never plant deeper than the top of the root ball. Make a water ring around the plant and water well to soak in the plant. After all the plants are in, apply a 3 inch layer of organic mulch or compost over the entire planting bed. Water 2-3 days per week, depending on your climate and plant material, until the plants are established (usually 2 summer seasons).
If you are using a drip irrigation system, run the main supply line by each plant. Do not bury. Use two emitters for each plant (in case one gets clogged). It’s best to insert the emitters directly into the main drip line (avoid using “spaghetti” tubing from the main drip line as this can also clog). Run the system to see if it is operating correctly. You may cover the irrigation lines with mulch but do not bury them. Run the system 2-3 days depending on your climate and plant material until the plants are established (1 or 3 gallon-sized container plants will need approximately 1 gallon 2-3 days per week. Larger shrubs and trees will need at least 5 gallons depending on their size). Once the plants are established, cut back on irrigation.
A water-wise landscape should require less maintenance than a traditional landscape once it is established. For the first year or two, your new landscape will probably require regular watering and a fair amount of weeding, but as plants mature, they should crowd out the weeds and develop deep roots. Each year apply a 3 inch layer of organic mulch such as bark, wood chips, or pine straw to suppress weeds. The mulch will also benefit plants by reducing evaporation and improving the soil. Your landscape may need proper fertilizing, pest control and pruning. As plants become established, maintenance should decrease and you can cut back on irrigation. See Lawn and Plant Care for additional information on maintenance.
Plant Purchase Tips
Select healthy, robust plants to get a solid start. Avoid “pot-bound” plants where roots are overgrown.
Bring your landscape plan with you to the nursery or plant store. Discuss your ideas with the local experts and select xeric plants that will work in your yard given the constraints of sun, shade, wind, water, etc.
Before you go to the store it is a good idea to identify the plants you are interested in. Browse the Garden Gallery and create a plant list of plants adapted to your local climate and site conditions. Note desired characteristics such as flower color and flowering time, foliage color and shape, and mature plant size. There are also many excellent reference books that can help you with selections. Many water utilities also offer brochures on locally adapted trees, shrubs and other landscape plants.