Published on 05/13/98

Twice the Landscape for Half the Water

Abundant rainfall throughout most of Georgia this spring has landscapes growing like gangbusters. Unfortunately, too much rain in some areas has raised havoc with newly transplanted ornamentals.

Junipers, in particular, have taken a beating. Junipers are extremely drought-tolerant once they're established. But they can't stand excessively wet soils for a long time.

Too much water can lead to the long-term decline or death of landscape plants. In fact, more plants are killed each year in Georgia from too much water than from too little.

Most well-established woody ornamental trees and shrubs can survive weeks without rain or irrigation. Light, frequent watering simply encourages root systems to grow near the soil surface.

That makes them more susceptible to drought stress and winter injury. Without irrigation, roots will grow deeper and extend two to three times their canopy spread exploring for water and nutrients.

Some herbaceous perennials actually prefer dry soils. Take purple coneflower, a plant native to the arid regions of the western United States. When irrigated, it tends to grow gangly, flop over and get powdery mildew disease. Without extra water, it thrives.

Rudbeckia hirta is another great plant for a nonirrigated site. Even if it were to die during a long drought, it usually throws enough seed each year to provide many happy returns.

Have you tried a plant called Gaura? It's one of those "got-to-have-it" plants, particularly if you're a low-maintenance gardener.

In my landscape, it thrives on a harsh, dry site, blooming from May to October. I cut it back in midsummer to force new growth and repeat blooms. Otherwise, I ignore it. And it loves the lack of attention.

Have you ever examined a day lily root and noticed the enlarged tuberous growths underground? These are like storage tanks of water and carbohydrates. They keep the plant thriving even during extended dry spells.

Irrigating day lilies is a waste of time and water. It will only encourage aphids and spider mites.

Perhaps only plastic plants are more drought-tolerant than ornamental grasses. Maiden grass, fountain grass and pampas grass are drought-tolerant machines. Their leaves may curl and turn bluish during drought, but they bounce right back with the first raindrops. It's foolish to irrigate these plants.

Although some plants are more water-efficient than others, plants alone don't save water. It's up to each of us. Our water resources are limited. If we'll all be more conservative, summer water rationing and bans on outdoor watering don't have to happen.

It's hard to imagine a drought when it's been raining cats and dogs. But I can assure you it will turn dry again in Georgia, and you will be tempted to water. Please think before you do.

Hand-watering container plants and annual flower beds will use less water than sprinkler irrigation. If you water in late evening or early morning, less water will evaporate. And mulching plants will keep the soil moist during dry times.

If you're irrigating more than 10 percent of your landscape, maybe it's time to redesign it or change your watering habits.

Through careful plant selection, siting plants right (as in sun or shade) and knowing plants' water needs, most people can cut their water use by 30 percent to 50 percent without sacrificing the quality or beauty of their landscape.

Having twice the landscape for half the water is a goal anyone can reach by learning simple ways to make every drop count.

To learn more about saving water in the landscape, get a Guide to Developing a Water Wise Landscape, complete with a recommended plant list, for $3.95 from the Georgia Water Wise Council, 1033 Franklin Rd., Suite 9-187, Marietta, GA 30067-8004.

Gary Wade is a Cooperative Extension horticulturist with the University of Georgia College of Agricultural and Environmental Sciences.