Summer drought and heat conditions can cause stress in landscape plants. Keeping plants healthy and keeping the water bill manageable requires a balance of sensible irrigation practices.

According to the Environmental Protection Agency, household water use increases around 60 percent in the summer, primarily because of outdoor watering. 

Also according to the EPA, about half of that water is wasted due to poor watering practices, such as watering sidewalks and streets, watering during rain or the heat of the day, and overwatering. 

Roots absorb water from moist soil, but wet leaves grow fungus. Apply irrigation as close to the soil as possible; this practice minimizes water loss to wind and evaporation as well as reducing fungal diseases. 

Drip irrigation is the best choice where it is practical, such in landscape beds and vegetable gardens. Drip tape and soaker hoses can be hidden under mulch, which also helps to conserve soil moisture.

Along the lines of reducing evaporation and leaf wetness, set lawn sprinklers to come on around 5 or 6 in the morning and turn off before 9 a.m. 

It’s cooler then, and morning sun and breezes that dry the dew will also dry irrigation water from the leaf blades. Established lawns typically need an inch of water per week. Watering deeply and infrequently encourages roots to grow deeper into the soil, where water lingers longer. Short, frequent irrigation sessions keep roots close to the soil surface. 

To figure out how much water your irrigation system of choice is supplying per hour, put a clean tuna can under the soaker hose or near the edge of the sprinkler reach. Turn on the water and let it run for 30 minutes. 

Turn off the water and measure the water collected in the tuna can and multiply by 2. If the can collects ½ inch of water in half an hour, then the system puts out one inch of water per hour.

Landscape plants have different water needs. Ideally, plants with similar water needs are grouped together in the landscape, allowing us to plan irrigation by hydrozones – high, medium, and low water need zones. 

In many landscapes, the zone with the lowest water needs, also called the xeric zone, is dominated by well-established trees and shrubs. 

These plants have deep, extensive root systems that can scavenge moisture from large areas of soil. They usually need supplemental irrigation only during extreme drought, heat, or long periods without rainfall, such as the three consecutive, utterly dry weeks we had last month. 

Following water-wise principles, the xeric zone should comprise 60 percent of the landscape. As this area is rarely disturbed, it saves on labor, too.

A transition zone of moderate water-use plants helps segue between the high and low water needs zones. 

Plants with moderate water needs include flowering native trees and shrubs, like redbuds and azaleas, as well as drought-tolerant herbaceous perennials, like day lilies and coreopsis. 

Watch these plants for signs of drought or heat stress, including wilting and leaves showing a yellow or gray color change, and hand water in the root zone of affected plants.

Annual bedding plants, vegetable gardens, and newly planted trees and shrubs have high water needs. For a water-efficient landscape, limit areas hosting these plants to a small portion of the landscape. For example, put flowering annuals in beds near the front door to make a welcome statement. 

Water annuals when the leaves begin to wilt. Apply one inch of water evenly around the root zone of newly-planted trees and shrubs each week. 

Join UGA Educator Shannon Kennedy at Post Road Library on July 13 to learn how Rain Gardens help manage stormwater, conserve water, and beautify landscapes.

UGA Extension strives to translate the science of life for use in everyday living. Forsyth County Extension is supported by the University of Georgia, Forsyth County Board of Commissioners, Forsyth County Board of Education, and United Way of Forsyth County.