Extreme heat can quickly kill the grass you've been working hard to maintain all year. Dry and dead grass can also catch fire with ease, which can spread quickly to your home. But with some preventative and corrective lawn care, you can keep your lawn, and therefore your home, healthy and safe.
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.
Warm-season grasses are originally from tropical areas of the world and, once established, are able to thrive in scorching sun and high temperatures. They grow most actively when air temperatures are warm, between 70 and 90 degrees F.
Heat stress occurs when the heat gets intense or long, and the grass begins to dry and die because it can't get enough water.
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.
Once your grass has come out of its dormant state, you may be wondering when you should start cutting it again. Generally speaking, if it is below 50 degrees Fahrenheit, it is still considered to be too cold to mow your lawn. The ideal temperatures to mow are between 50 to 80 degrees Fahrenheit.
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. Your turf should receive about 1/3 an inch of water every two days in order to maintain deeper roots, thus helping protect against drought.
Don't water everyday.
Watering everyday makes grass roots shallow. The more shallow your grass roots are, the less hearty it will be in hot weather. Instead water about two times per week for longer periods of time.
As the heat starts to put stress on your lawn you may notice full brown blades of grass or grass with brown tips. They may have begun to curl.
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.
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.
Grass needs the benefit of the day to dry and heal before dusk settles. Since mowing your grass in the early morning can damage it and mowing it during the early afternoon can burn it because of all the high temperatures, the ideal time is mid-morning. That is of course if you're free during that time of day.
In fact, some cool-season grasses will go dormant during the hot summer months until early fall. During a heat wave—a period of abnormally hot weather that lasts longer than 2 days—it's recommended that you do not mow your lawn.
WATERING SCHEDULE
Deep watering helps to encourage deep root growth. Deeper roots stay cooler and stronger to better protect your lawn and garden from heat stress. Allow a deep watering at least once per week, twice if the temperature exceeds 100 degrees or more for several days in a row.
Highlights. 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.
To determine how long you need to water to get one inch, place a plastic container in your yard and set a timer. On average, it will take 30 minutes to get a half inch of water. So, 20 minutes, three times per week will give a lawn about an inch of water.
This may seem like a no brainer, but watering grass during extreme heat is the single most important thing you can do to keep it alive. We recommend watering daily with heat like this, but please be sure to abide by local regulations for water usage in your state. It also matters what time of day you water your lawn.
In times of extreme heat, it is vital to water your lawn for about 30 to 45 minutes daily. Once the temperatures drop below ninety, you can cut back to watering three to four times a week, until that blissful thunderstorm comes and quenches your lawn's thirst!
Mowing high gives the lawn a deeper and larger root system, keeps moisture in, defends against weeds and keeps the soil cooler. Mowing too short during dry conditions can injure or wear out dormant grasses to the point where they may not come back during cooler conditions.
It may seem obvious, but keeping your lawn watered is critical for lush and green grass. You'll need to assure your lawn gets 1 inch of water per week. If it's not raining regularly, set up a sprinkler. Alternatively, make watering your yard part of your morning routine.
There is no way to revive dead grass, but you can lay new sod to grow your landscape again from scratch. If you notice brown, bare, or thinning areas in your lawn, these are clear signs that you need to sow new seed or replace the sod.
Cool-season grasses will go dormant to protect itself when it becomes too hot and it receives too little water. Warm-season grass will go into a dormant phase when extremely cold weather arrives. The grass will technically die naturally but will grow back when warm weather and proper watering occurs.
Grasses that typically need warm temperatures between 75-90°F grow the most during summer months. As a result, they become dormant in cooler seasons which causes their brown color and ragged texture. To take advantage of their prime growing months, warm-season grasses should be seeded just before the start of summer.