Watering Landscapes
Texas Cooperative Extension
Revised 6 July 2005 by Dr. Doug Welsh

Probably the most important concept in landscape water conservation is proper watering. Knowing when to water and for how long is fundamental to maintaining a quality landscape that is water efficient.

Newly planted trees and shrubs will need more frequent watering from the planting time until they are well-rooted. During this establishment period, plants can be gradually weaned to a smaller amount of water. Proper weaning develops deep roots and makes plants "drought enduring."

Of the tremendous amounts of water applied to lawns and gardens, much of it is never absorbed by the plants and put to use. Some water is lost to runoff by being applied faster than the soil can absorb it, and some water evaporates from exposed, unmulched soil before it can be used by the plant. Yet the greatest waste of water is when too much is applied too often. More plants are killed by too much water than by too little.

Most lawns receive twice as much water as they require for a healthy appearance. It is best to not water by the calendar, for example, once a week. It is better to water when the plant needs watering. Most gardeners can readily recognize lawn stresses due to lack of water, such as wilting and yellowing. The key to watering lawns is to apply the water as infrequently as possible, yet thoroughly.

As with lawns, trees and shrubs should be watered as infrequently as possible, yet thoroughly. Most established trees and shrubs will benefit from a twice a month thorough watering during the growing season in the absence of adequate rain. Normal lawn watering is not a substitute for thorough tree and shrub watering.

There are two types of irrigation systems for use in landscapes -- sprinkler and drip irrigation. Within a Xeriscape, it is recommended to use a combination of both systems in watering turfgrass, trees, shrubs, ground covers, flowers and vegetable gardens.

When properly utilized, irrigation systems should give plants a sufficient amount of water without waste. In addition, planting areas which have a higher water requirement can be watered separately from lower-water-use plants by zoning the irrigation systems.