When to water your lawn in summer's heat

7/11/2007

Do you see gray footprints in your lawn when you walk through it?

Your lawn could be telling you it needs more water. If it is cut at the recommended height of 2 to 3 inches, footprints should bounce right back up. But if you can still see your boot mark, it's time for some water.

A dry lawn will turn purplish-blue first. If left dry too long, it will turn brown. Brown is also the sign that your lawn is going into dormancy to wait out the summer heat.

Water your lawn on a regular basis for longer periods to get the water deep into the soil, rather than frequent short watering. Scientists say this encourages longer root growth. When turf has longer roots, it will be able to withstand a drought better.

The best time to water is in the morning. Less moisture will evaporate into the air and the sun will have all day to dry the blades. If there are a few puddles around the yard, you have watered it too fast and the soil couldn't soak up the water fast enough. Chances are the places with standing water are on the heavy clay side rather than sandier soil.

Maintain a consistent rate of spray to let the soil absorb it. Heavy clay soils will take more time to absorb water, but hold it longer. Sandy soils will absorb the water quickly, but need to be watered more often.

Some diseases pop up during dry spells. Dollar spot can be a common problem. Round, yellow spots will appear in your lawn. They are usually 2 1/2 inches across. Some can grow to 8 inches or more in diameter. If you don't treat them, these patches can turn into sunken areas with a red-brown border. When the weather turns wet, these areas may cover over with a white mold. Dollar spot is common in turf with heavy thatch buildup or low nitrogen and potassium levels. Some of it can be wiped out with a boost in the fertilizer.

Take a close look at your grass. If it has lesions or spots on individual blades close to the tip, it may be caused by a fungus that will girdle the blade of grass. These spots are usually bleached white with a dark brown edge. It won't hurt the root, but it can stunt their growth.

To fight this disease, keep feeding it and then follow with a regular watering plan. Most turf experts say a good dose of fertilizer and water will help the plant grow right out of this stress. For a quick fix, treat the area with a fungicide. Test the soil and give the lawn nutrients it is lacking.

But don't do it just yet. Fertilizing in the hot summer will hurt the turf more than help it. When you fertilize, you are encouraging root growth and plants take up more moisture. Wait to beef up the fertilizer plan until the temperatures cool down again in the fall. Give them another thin layer of compost or water-soluable fertilizer in September or October. Then give your lawn its last "slow-release" feeding for the year around Thanksgiving.

How much?

Give your lawn about an inch of moisture at each watering. The timing all depends on the water pressure at your house.

Here's an easy way to gauge how much water your lawn is getting. Put a flat container such as a clean tuna can out in the yard within the sprinkler's reach. Turn on the sprinkler and mark down the time. Keep checking the tuna can; when it has an inch of water in it, you can turn it off. That will be how long it takes for your waterline and sprinkler to deliver the proper amount of moisture to the lawn.

Contact Kelly Heidbreder at:

kheidbreder@theblade.com.