Protecting Your Lawn During a Heatwave

High temps and dry weather: It’s great for beach days, backyard barbecues and Sunday afternoon picnics. What it’s not ideal for, however, is your lawn. While summer weather can certainly help encourage growth if you have warm-season grass, extended periods of high temperatures can result in heat stress if you have a cool-season lawn. Heat stress is a concern mostly for cool season grasses (bluegrass, ryegrass, tall fescue) that prevail in the Northern and Transition zones rather than the South, where warm season grasses dominate. 

Heat stress, as you could probably guess, occurs when your grass gets too hot for too long, which occurs during extreme temperatures in the 90s (or above). Mitigating factors for how quickly heat stress might occur include humidity levels, your lawn’s natural shade, irrigation, the overall health of your lawn, and your watering patterns. The stress of being overheated for an extended period can cause your grass to wilt and weaken. The stress combined with dehydration from drought conditions can cause your grass to take on a light brown appearance, and send your lawn into a summer dormancy as the grass plants conserve energy and resources (grass dying from heat stress, fortunately, is less common). 

However, it’s important to keep in mind that a lot of the visible signs of heat stress are similar to those of some common lawn diseases. As such, if you’re noticing discoloration or poor growth on your lawn, your first course of action should be to consult your local TruGreen lawn care expert. They’ll take a close look at your grass and determine what the problem is and prescribe the proper course of action to help restore your turf’s health.

When humans get overheated, we sweat. It may feel unpleasant, but the moisture serves a purpose: It cools us down. Grass, however, can’t sweat. What it can do is pull moisture from the soil to cool itself off. Hot, dry temps, however, can dry out the soil. Without adequate moisture, grass has no way to cool itself down, ultimately leading to heat-induced drought stress.

The solution, then, seems simple: If moisture can mitigate heat stress, all you have to do is water your lawn — right? The truth is, it’s not quite as straightforward as that. It's important to supply your lawn with enough water to support healthy grass plants. But, the symptoms of heat stress can sometimes look like those of drought stress. One tip is to irrigate in the morning, when winds are generally lighter and dew is often already present. You’ll want to irrigate your lawn enough to supply 1 to 1.5 inches of water per week. Watering too much during hot weather can be just as detrimental as not watering enough. 

Mowing is also an important consideration where lawn care is concerned — especially when it’s hot out. While regular mowing can help keep your lawn healthy, care should be taken if your turf is experiencing (or vulnerable to) heat stress. The longer your grass is, the more water it can hold on to — and in turn, the better it’s able to keep itself cool. Our advice is to raise your mowing height during periods of hot weather. Mow your lawn only when it's tall enough to be cut and avoid mowing during the hottest portion of the day.

As we’ve established, watering your lawn (especially early in the morning) can help protect your lawn during a heat wave. But it’s not 100% preventative. So, what happens if your lawn does get over-stressed from the heat? Can you get burnt grass green again? 

A healthy, dense lawn is the best defense against the stresses of summer - namely heat and drought. That being said, there’s no one-size-fits-all approach to lawn care. TruGreen's experts know what it takes to make your lawn healthy and prepare it for summertime stress. We’ll work with you to tailor a plan that suits your needs — so you can spend more time enjoying your outdoor living space, and less time worrying about it.