While warm-seasons lawns have generally responded favorably, the cool-season grasses are not so pleased with the major heat wave our area has recently received. The tropical weather like patterns coupled with late afternoon thunderstorms have created a decline in the quality and performance of the cool-weather grasses such as Kentucky bluegrass, tall fescue, and perennial ryegrass.
Many of the significant cool-season turf will display signs and symptoms whether the problems are caused by living or non-living entities. Brown Patch (Rhizoctonia Blight) pm tall fescue grass is the most common turf disease during the summer in Virginia. Diseased turf will have random patches of blighted grass which may or may not have circular patterns. A truly diseased turf will, most likely, need a chemical control strategy, although with something as seemingly unsightly as brown patch, it will not typically kill the turf-grass plant and the grass will generally recover as cooler temperatures arrive.
What can be done during the heat? Very often the answer is nothing; when cool-season turf is under stress during the extreme heat or extreme moisture, it is often best to leave the turf alone. Since some people prefer action, below is a list of important tips for surviving the summer heat:
- Remove all traffic and raise the cutting height to the highest setting. Refrain from mowing until temperatures are more moderate and new growth has appeared.
- Choose an appropriate watering strategy. Apply no water at all or water deeply and infrequently. Let your lawn enter its natural dormancy state and stay off the lawn with both foot traffic and equipment during this time.
- If you suspect a disease, call a turf expert.
Information gained from Virginia Tech College of Agriculture and Life Sciences: Virginia Cooperative Extension