Most turf grasses are 70 to 75% water, which tells you the importance of moisture in maintaining a healthy, vigorous lawn. If the grass plant loses more water through the leaf blade than the roots pick up, the lawn becomes stressed.
When a lawn becomes drought stressed the leaf blades turn from a bright, healthy green to a dull grey colour. Lawn mower tracks and foot traffic will leave marks for a longer period of time. This is due to the plant bending over and not recovering to an upright position. As stress continues the lawn will change from a dull grey or bluish colour to more of a yellowish and finally a tan colour. Tan is a clear marker that the lawn is in drought dormancy.
Although a weekly mowing schedule is recommended for a healthy vigorous lawn, it is not for a lawn in drought stress. Because of the low moisture content in the leaf blade, mowing or foot traffic can cause the cellular structure to collapse. Broadleaf weeds love a lawn in drought stress as they are more tolerant of low moisture conditions and create an opportunity for the weeds to gain a better foothold.
DROUGHT STRESS SOLUTIONS:
There really is no miracle cure for a drought stressed lawn, other than moisture, moisture, and more moisture. If you are unable to water enough to keep your grass green, try to water once every 7-14 days with approximately ½ of an inch of water. If the signs of drought are persistent, do not mow during the hot weather.