By Brad Haire
University of Georgia

Georgia has had plenty of rain in the past month. But there's no guarantee it will be plentiful all summer. And just two weeks without rain can be enough to hurt most grasses.

Your lawn doesn't have to suffer, said Kerry Harrison, an irrigation specialist with the University of Georgia Extension Service. But you don't want to just turn on the sprinklers anytime you feel the lawn needs a drink. This could waste water and damage lawns. It could get you in trouble, too.

The guidelines

Georgia has no mandatory watering restrictions statewide now, he said. But there are some guidelines.

If your street address is an odd number, you're asked to water on Sunday, Tuesday and Thursday. If it is an even number, you're asked to do it on Monday, Wednesday and Saturday. "There's no outside watering on Friday," he said.

New automated irrigation systems, Harrison said, must be equipped with rainfall sensors to stop them when it rains. Watering guidelines are enforced by local authorities.

But homeowners can easily supply their lawns with needed water and still follow the guidelines, he said.

Know the system

It doesn't matter if you use a permanent system or a sprinkler attached to a hose. The first thing you need to know is how much water you're applying and how fast.

"Not knowing your water application rate is like driving a car with no speedometer," he said.

Different systems apply water at different rates. Hose-sprinkler systems vary the most. Space three rain gauges within the watering area of your system. Look at your watch. After an hour has passed, check your gauges to see how much water your system puts out in that time.

Good timing

Most lawns grow best when they get 1 inch of water a week, either from rain, irrigation or combination of the two. And they prefer long soakings. In dry weather, water only once or twice a week to get that 1 inch of water.

Light, frequent watering can cause turf grasses to develop shallow roots. This can lead to many problems, including disease and insect damage and discoloring from poor fertility.

The grass at the very end of a sprinkler's trajectory may not get as much water as the grass closer to the sprinkler. Permanent systems should be set for overlap in sprinkler patterns to adjust for this. Remember this when you move your hose-sprinkler system. You want your lawn to be uniformly wet.

Water at the right times, too: early morning or late at night, Harrison said. If you don't, you could just waste time and water.

"We have research and evidence to show that you can lose as much as half the water if it's applied during peak daylight hours," he said.

High temperatures and high winds can evaporate water or blow it off-target, too, he said.

Watering during the day, too, increases the time grass is wet. This can cause disease. Watering at night won't hurt grass that's already wet from dew. The turf gets the water it wants and is drier during the day.

Georgia should have a typical, humid summer with temperatures in the mid-80s and 90s and spikes around 100, said state climatologist David Stooksbury, a professor of engineering with the UGA College of Agricultural and Environmental Sciences. The heat should generate hit-or-miss afternoon thunderstorms.

An above-average tropical weather season is forecast for the Atlantic Ocean. But fewer storms than in 2004 will likely make landfall.