8 Ways You Can Help Your Lawn Survive the Heat Wave

Unusual weather events are quickly becoming the new normal. This includes more extreme heat waves that bring days of intense temperatures. Typical lawn care methods won’t cut it during a heat wave, and need to be adjusted. If you’d like to learn ways to protect your grass from heat, read on for pro-tips from Joe Churchill from Reinders and Matt Cameron from CMS Landscaping.

Raise Mower Blades

If you must mow your lawn during a heat wave, raise the blades first. Longer grass helps shade the soil and prevent it from drying out as quickly. For cool-weather grasses, aim for a blade height of 3 1/2 to 4 inches. For warm-weather grasses, a 3-in. blade height is ideal.

This is especially true for cool weather grasses. “Cutting these grasses short in summer months puts additional stress on the plant,” Cameron says.

Provide Temporary Shade

If you have a section of lawn that bakes in the sun all day, consider setting up some temporary shade. Sun sails and pop-up canopies can protect your grass from heat during periods of intense temperatures.

Limit Foot Traffic

During a heat wave, grass is more vulnerable and less durable. To avoid overstressing it, try to limit the amount of foot traffic on your grass.

Water Deeply

Long, infrequent watering is better for the overall health of your grass, especially during drought and heat. This practice trains roots to grow deeper into the soil, looking for groundwater.

These longer roots come in handy during a drought or heat wave.”When lawns are overwatered, most of the grassroots are in the top one inch of soil or so,” Church says. “That makes your lawn less drought tolerant and unhealthy.”

Church recommends watering your lawn thoroughly in the morning before the temperatures rises. Aim to provide at least 1 inch of water per week during a heat wave.

Avoid Fertilizing

Fertilizer can overwhelm already stressed grassroots and greenery, so skip it during a heat wave. It also encourages new growth that is not hardy enough to withstand a heat wave. Save your fertilizer for cooler temperatures.

Mulch Grass Clippings

If you must mow, Cameron recommends mulching grass clippings. This helps protect grass from heat by retaining moisture and moderating soil temperatures.

Skip Lawn Mowing

If possible, don’t mow your lawn at all right before a heat wave is expected nor during it. Longer grass shades the soil and is more resilient during times of stress.

Add a Layer of Compost

A thin top dressing of compost can also protect your grass from heat. It will aid in moisture retention in the soil below, where grassroots need it most.

Keep the layer 1/8 inch thick and spread it evenly across the lawn. Thicker layers could kill grass, especially in high temperatures. Compost is most helpful when layered on the soil, so avoid any clumps on grass blades if possible.

Frequently Asked Questions

How hot is too hot for grass?

Cool and warm-weather grasses respond differently to hot weather. Cool grasses start to stress when temperatures reach over 85 degrees Fahrenheit. Warm-weather grasses, like Bermuda Grass, can withstand temperatures of 100 degrees Fahrenheit or higher before showing signs of stress.

About the Experts

• Joe Churchill is a Senior Turf Specialist for Reinders, a major distributor of lawn care products throughout the Midwest. Churchill is certified in Turf Management and has over 25 years of experience in the turfgrass industry.
• Matt Cameron is the owner of CMS Landscaping, a full-service lawn care and irrigation company in Holyoke, Massachusetts. Matt has 15 years of landscaping experience.