May 2, 2001 | By: Haven Miller
LEXINGTON, KY.

If your county is suffering from lack of rain, you may be tempted to start heavily watering your trees and shrubs. But if you're not careful you can do more harm than good.

"Certainly trees and shrubs need water, especially newly-planted trees, but soaking your woody plants every day can be harmful," said Bill Fountain, UK Extension horticulture specialist.

According to Fountain, young trees should be thoroughly soaked at planting time, and then watered only once or twice a week through the summer when rain is insufficient.

"For young trees you've recently planted, the idea is to keep the soil ball moist but not to water so much that you drown the roots and encourage root diseases," he said.

If you're choosing a new tree, it's important to match the tree to the site, and also install it properly. After planting it should only be watered when it really needs it. Older trees require very little watering in normal summers, and only an occasional soaking during drought.

"With our larger more mature trees, we want to let them go into dormancy during drought," Fountain said. "When the tree isn't getting enough rain, it survives by going into dormancy and getting its moisture from deeper in the ground. But if we constantly water that older tree and then suddenly we're put under water restrictions and can't water as often, then we're putting that tree in real danger because it can't make the transition."

Fountain said when water use is restricted, people sometimes apply more water rather than less, and that can lead to problems.

"When people are told by their water company to go to an every-other day system, they worry about skipping days and often think they must definitely water plants every other day," Fountain said. "The problem is that trees simply don't need to be watered every other day, even during dry conditions. That's what we mean when we say people should learn to be good stewards and good gardeners and know the needs of their trees and shrubs."

Fountain said drought conditions can sometimes cause annual plants to die, but annuals can always be planted again next year. He said perennial plants, such as trees and shrubs, are a much bigger investment and therefore need to be treated with care.