The recent rain was great, but with high temperatures we may soon be back in drought conditions. You cannot completely "drought-proof" your landscape, however, steps can be taken to help plants survive periods of limited rainfall. The most obvious way is to select and grow plants known to have a high degree of drought tolerance. There are also a number of cultural/management practices that will help conserve moisture in the soil and minimize the amount of water-demanding new growth.
First, make certain plants have a generous supply of mulch over their root system. Three to five inches of mulch will help hold moisture in the soil and prevent evaporation from the soil surface. Fine-textured mulches, such as pine straw, mini-nuggets and shredded hardwood mulch do a better job of conserving moisture than large particle mulch. Apply mulch to as large an area as possible under the plant, remembering that the roots of established woody ornamentals extend two to three times the canopy spread.
Avoid cultural practices that encourage new water-demanding growth. Fertilization is not wise during extended dry periods because fertilizers are chemically salts and can actually help dehydrate the roots of plants. Routine pruning also stimulates new growth and should be avoided during dry periods.
However, some selective pruning may be necessary.
When drought occurs and watering restrictions are enforced, you may have to decide which plants to water for survival purposes. Newly planted trees and shrubs (those installed within the past four months) should be a priority simply because they do not have a well-developed root system. Also, some established ornamentals have less drought resistance than others and should be your priority list for watering. These include dogwood, sugar maple, hemlock, white pine, Japanese maple, birch and spruce. Consider the replacement-cost value of plants when deciding what to water.
The worst thing you can do for plants is to water them frequently and shallowly. Shallow, frequent watering encourages a shallow root system and reduces the drought tolerance of plants.
When you water, direct water to the roots and avoid wetting the foliage or ornamental plants. Wetting the foliage not only encourages diseases but also results in evaporative loss of water.
Drip or trickle irrigation or a soaker hose are efficient ways of watering. Drip irrigation uses 50 percent less water than conventional sprinkler irrigation and applies water slowly and directly to the root system.
A timer installed on outdoor faucets to control the period of irrigation will prevent the unnecessary use of water.
Remember, many of our Southern ornamental plants have an inherent tolerance to drought and can survive periods of limited rainfall.
Clark Beusse is the Dawson County extension agent. For more information, call (706)265-2442.