Summer heat stresses lawns. With proper watering and attention, however, you can keep your grass green and healthy. Consider these tips.

* Measure as you water. Lawns require as much as one-third inch of water per day, or 2.5 inches per week in mid-summer. To measure water application and help determine length of watering time, place a 6-inch deep, or more, straight-sided can in several locations around the lawn. Run sprinklers, then measure the water in each can and average the results. Also keep track of how long it takes to fill the can with the right amount of water so you can determine length of watering time.
* Be aware of water penetration. Water should penetrate about 8-10 inches per application. To determine depth of water penetration, push a rod or screwdriver into the turf and measure how far it goes in. Water deeply and as infrequently as possible. Too much water causes iron chlorosis or yellowing in turf, trees and shrubs. It also carries away fertilizer.
* Know your soil type. This will help determine frequency in watering. In mid-summer, sandy soils need to be watered about every two days. Loamy type soils need water every three to four days, and clay soils need water every four to six days.
* Watch your mowing height. This is an important factor in minimizing lawn stress. Keep the lawnmower blade adjusted at 2.5 to 3 inches. This will reduce water loss to the grass. It will also help keep turf and roots thick, which will reduce weeds. Keep the mower blade sharp to prevent lost moisture through ragged grass blade tips.
* Fertilize your lawn every four to six weeks throughout the growing season. A properly fertilized lawn needs one pound of nitrogen applied per 1,000 square feet.