How To Save Water In Your Garden and Landscape

BY JANET HARTIN, Environmental Horticulture Advisor, UCCE
and DONALD R. HODEL, Environmental Horticulturist, UCCE

Did you know that you can save 20 to 50 percent of the water your are currently applying to your garden and landscape plants and actually improve their health, productivity, and appearance? Many people think that to save water they need to replace their current landscape with strictly "drought tolerant" plants and perhaps remove their lawn altogether. While drought tolerant landscapes and lawn removal could be useful options, they are just two of the many strategies that can be employed to reduce water use. By employing the full range of water-saving strategies, you can grow most plants adequately while still realizing substantial water savings.

Remember that trees provide beauty, shade, cooling, privacy, and oxygen. They can also significantly increase property value. Even when water is in short supply, taking care of your trees should be a high priority. Try these water-wise tips:

• When selecting plants, consider their climatic suitability for the site. There are many books and other publications you can consult for recommended plants in your area.
• Check your sprinkler system for leaks and make necessary repairs to ensure even distribution and avoid water loss
• Water early in the morning before sunrise to reduce evaporation.
• Avoid watering during windy times of the day to reduce uneven distribution, evaporation, and water waste.
• Control weeds, which compete for water, light, and nutrients.
• Fertilize moderately, applying the low end of recommended rates, to avoid excessive growth, which increases the need for water.
• Apply three to four inches of mulch around trees and other woody plants, keeping it a few inches away from trunks and stems. Mulches reduce water evaporation from soil, buffer soil temperatures, and reduce weeds. Apply or renew mulches in late spring when soils have warmed up and water demands are increasing. Use backyard compost, decomposed lawn clippings, shredded bark, fir bark, composted manure, or other bagged products. Decorative gravel can even be used in places not subject to soil cultivation. Remember to water through the mulch and into the root zone.
• Reduce runoff on slopes by cycling water in several short intervals. Apply water only until runoff begins. Wait an equal amount of time then repeat watering until runoff begins again. Repeat this cycling until the soil has been moistened to about one foot deep. Clay and other heavy soils are especially prone to runoff. Use low-flow sprinklers (less than 1/2 inch output per hour).
• Prune trees and other woody plants only when necessary. Pruning stimulates shoot growth, which increases the need for water.
• Water trees and other woody plants separately from the lawn, if possible, since it is best to water them less frequently but more deeply than lawns. A garden hose, mini- or micro-sprinklers, deep-root irrigator, or drip emitters all work well for trees and other woody plants.
• Water trees and other woody plants to a depth of two feet to help promote a deep root system. You can use a soil probe, screwdriver, auger, or straightened coat hanger to find out how deep the water reached. These tools will readily penetrate a moist soil, but will resist penetration in dry soil.
• Consider installing a drip system that applies water through emitters directly at the root zone where it is needed most and not wasted.
• The type of soil you have largely determines how often you should water. Clay soils hold much more water than sandier ones, but take it up more slowly; therefore, they can go longer between waterings than sandy soils. Clay soils may only need to be watered once during a given period while sandy soils may need two or three waterings during the same time. Add organic soil amendments to sandy soils, such as those used for mulches, and thoroughly mix them into the upper foot. Although these amendments will not decrease the plant's water need, they can usually increase the water-holding capacity of the soil and the interval between waterings.
• Aerate lawns and ground around trees and other plants by removing small plugs of grass and/or soil to prevent compaction and increase water absorption. Most local rental businesses can provide soil.
• Aerators. Clay and other heavy soils especially benefit from annual aeration.
• Remove the accumulation of old grass roots, stems, and leaves, called thatch, on your lawn, which acts as a barrier to keep water out of the soil. Remove thatch in spring, before temperatures get too warm, if it is more than 1/2 inch thick.
• Mow your lawn at the correct height: Common Bermudagrass 1 inch; Hybrid Bermudagrass 1/2-3/4 inch; Zoysia 3/4-1 inch; St. Augustinegrass 3/4-11/4 inches; Tall Fescue 11/2 -3 inches; Perennial Ryegrass and Kentucky Bluegrass 11/2 inches.
• Check faucets, hoses, and sprinklers for leaks. A new rubber washer is inexpensive and easy to install.
• Use the Lawn Watering Guide of the Garden Information Series to schedule waterings.