Typical warm-season grass height range: 1-3 inches. During periods of peak growth, expect to mow the lawn once every 5-7 days. Conversely, during times of slowest growth, you'll mow less, if at all.
AVOID MOWING DURING EXTREME HEAT When your lawn is particularly stressed from heat or drought, it can be limited in its ability to recover from mowing and can be damaged even more. Instead, mow the grass after a rainfall or after irrigation day.
Yes, it can be. The heat leaves your grass 'stressed' and cutting it too often or too short can make this worse. If you do mow, try doing so a day or so after it rains, when your grass is likely to be happier.
So, what's the best time of day to mow a lawn in hot weather? Plan to mow your lawn during the evening hours, after the heat of the day has passed. The temperature should be between 40°F and 80°F.
Once temperatures reach 77 degrees, it becomes too hot for root growth, and root growth ceases. When temperatures reach 90 degrees, it becomes too hot for shoot growth and the grasses stop growing and begin to fall dormant, with the surface grass turning a brown hue.
Bermudagrass is extremely heat tolerant — daytime temperatures of 95 to 100 degrees Fahrenheit are optimal. Pennington Bermudagrass yields dense, resilient, heat-tolerant lawns. Zoysia grass, Centipede grass and Bahiagrass also tolerate high heat very well.
Grass generally stops growing once temperatures drop to below the range of 50-55 degrees Fahrenheit or reach above 90 degrees Fahrenheit.
Mower Height
A mowing height between 2.5 to 3 inches is best for most of the season, except during summer stresses when the lawn mowing height should be raised one-half inch to mow at 3 to 3.5 inches. Raising the mowing height provides more insulation from summer heat and reduces water loss from your soil.
Try to water deeply and infrequently. Watering deeply means wetting the entire root zone. Watering infrequently means only watering when the grass is dry. Try to water early in the morning when your lawn can get the full benefit of hydration before the sun dries it out by mid-day.
Check the soil: If the it looks muddy or feels soft, it's usually better to wait. Ideally, you should wait until the grass is dry enough so that you can walk through the lawn and not have wet shoes.
Keeping your grass short makes its life more difficult. A smaller surface area permits less exposure to air and sunlight, which means less photosynthesis and less energy. A weakened blade leads to weakened roots, which are more vulnerable to insects and diseases.
Reinvigorate Your Lawn
By spreading grass seed over your existing lawn, you can thicken up the thin areas, and your lawn will start to look terrific again.
So, how often should you water your lawn in the summer? The answer may surprise you. Between irrigation and natural rainfall, your grass should receive between 1 and 1.5 inches of water each week during the summer. Water deeply every other day for the best results.
The best month to put grass seed down depends on the type of grass you have. The best time to plant grass seed for cool-season grasses is in early fall or around September. For warm-season grasses, late spring or early summer is the optimal time.
The most heat-tolerant grass species include Bermuda grass (especially varieties like common Bermuda, 'Celebration,' and 'GN1'), zoysia grass, St. Augustine grass, centipede grass, and bahiagrass. Despite being cool-season grass, buffalo grass also performs quite well in the heat.
Bermudagrass is ideal for hot and dry areas because once established, it tolerates both conditions very well (though it will need some water to stay green in arid environments). A finely textured turfgrass that grows best when maintained at 1-2 inches in height, bermudagrass requires full sun for best growth.
Avoid watering grass on a hot afternoon when it's 95 degrees or higher. The best time to water grass is at dawn or in the early evening. Water deeply three times a week instead of a little water daily.
Consequently, if the temperatures reach 95 degrees Fahrenheit or higher, you will want to avoid watering your lawn. Keep in mind, your water from the sprinkler system will evaporate off the grass so quickly, that it will not have time to seep into the root system.
Most oscillating sprinklers will put off about one inch of water an hour. That would mean that you would need to water your lawn for one hour, once a week (twice weekly in periods of extreme drought). For less established lawns, you may need to increase the frequency as your lawn's root system becomes more robust.
It's best to wait for wet grass to dry before mowing. Wet grass clippings can clog your mower, causing it to choke and spit out clumps of wet grass that could smother and kill your lawn if left unraked. It's best to wait for wet grass to dry before mowing.