Mowing Lawn in Hot Weather: What do You Need to Know?


For anyone living with a lawn, mowing it is a pretty regular chore, right?

But what about in the heat of the summer? Or the middle of a drought? Heatwaves even? Should you be treating your lawn differently during times like these?

The short answer is yes! Definitely! So when should you mow your lawn in hot weather?

Keep reading!

I’m going to explain the ins and outs of looking after your grass in the summer so that you can enjoy a healthy lawn all year round and not create more work for yourself.

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Key Points

  • How you treat your lawn depends on the grass species.
  • Mow last thing at night in hot weather.
  • Mow a little longer.
  • Don’t waste water on irrigation.
  • Don’t fertilize or spray for weeds in the heat.
  • Minimize other forms of stress.

Warm Season Versus Cool Season Grasses

There are a number of things that you should do differently when it comes to looking after your lawn in hot weather.

When I say hot, I mean anything above 80˚F.

But what exactly you do differently will depend on the type of grass your lawn is composed of.

person mowing lawn in summer

Lawn grass species are divided into either cool-season or warm-season grasses.

If your lawn is composed of cool-season grasses, as most are, it will likely go dormant in the summer. This means that it will be under stress in the heat and will stop growing in order to survive the summer. It may look dead, but it’s not. Instead, it has simply transferred energy and moisture to its roots and allowed the leaves to turn a yellow color.

While it’s tempting to try and revive dormant yellow grass, you may be doing your lawn and the environment a disservice.

Don’t Waste Water on Irrigation

Drinking water is a precious resource that is often in limited supply in the summer. Using it to water your lawn during a heatwave or drought is not a sensible or kind thing to do.

If you must irrigate, be sure to only do it late in the evening once the temperatures have dropped to avoid losing water to evaporation.

Set up a sprinkler to run once or twice per week and water deeply, rather than daily but with a shallow watering. This will allow the water to penetrate to the roots and support the health of the grass, rather than being restricted to the surface and drying out during the day.

Installing a rainwater tank is also a great investment. It may not help you out much over a long dry summer but you’d be surprised how much you can collect from a small roof. You then have this on hand to irrigate your grass without using up drinking water.

rainwater harvesting barrel

Another option is to consider mixing up the species in your lawn. Did you know that clover often stays green long after the grass has turned brown in the summer?

Don’t Fertilize During the Hot Season

Applying fertilizer or selective herbicides on your lawn in the summer while it is dormant will likely do more harm than good. It’s important to only fertilize plants during their active growing season, which for cool-season grasses is fall or spring.

The exception to this would be if your lawn is composed of warm-season grass and your region is experiencing enough rain for healthy growth. Then, by all means, give your lawn a feed in the summer.

What Time of Day to Mow in Hot Weather?

Since most lawn species are cool-season grasses, they are unlikely to actually be growing in the heat of summer. This means you shouldn’t actually need to mow your lawn in really hot weather.

The most sensible thing you can do for your lawn is actually to just leave it alone when the weather is above 80˚F.

But assuming your lawn is unreasonably long and really, really needs a trim, the best time of day to do it is last thing at night after temperatures have dropped. This also allows the grass to have the cool nighttime to recover and hopefully benefit from a little morning dew before the heat of the day returns to stress it out all over again.

Now that we’re on the subject, do you need a new mower? I have guides and reviews of every kind of mower you could think of so look no further! Whether its battery-powered mowers, ride-on mowers, commercial zero-turn mowers, or mowers for small yards, I’ve got you covered!

If you’re not sure what kind of lawn mower you need, I have a guide to the different kinds of lawn mowers that is an essential read.

Mow a Little Longer

Assuming you decided that you did need to cut your grass, aside from waiting until the evening has cooled down, it’s really really important to raise the height of your mower blades and not cut the grass as short as you would throughout the rest of the year.

mowing the grass with a push lawn mower in garden

Why?

Leaving your grass a little longer in hot weather actually helps to protect it.

Longer grass has longer roots which will mean it is better able to access water that is deeper in the ground.

Longer grass is also able to provide a little shade for itself and help to keep itself and the soil a little cooler.  Lastly, longer grass doesn’t dry out as quickly so it should stay green a little longer too.

Are you looking for a lawnmower on a budget? I have a great list of cheap lawn mowers that will help you out. And don’t forget your hearing protection!

Other Tips

If you have a cool-season grass variety and you’re reading this in the middle of a hot summer, chances are your grass is already stressed. Minimizing other forms of stress can help the grass to retain its strength and bounce back once the weather cools and the next growing season arrives.

Tips to limit other stressors include:

  • Limit foot traffic or vary it to different parts of the lawn to prevent dead patches from appearing in high traffic areas.
  • Remove lawn furniture, garden toys and equipment at the end of the day and replace them in a different position the next day. Air movement across the grass is really important for its health in hot weather.
  • If you do mow your lawn and the volume of cut grass isn’t too great, leave the grass clippings on the lawn as mulch (assuming they have sprinkled nicely and aren’t clumped). They will return their nutrients to the ground and help to retain moisture in the soil. Check out this article for more ideas on what to do with grass clippings.
  • Make sure your lawnmower is up to the job and well maintained. If you need to brush up your lawn mower maintenance skills, have a read of this article. If you already know your blades need sharpening, I have a guide to the best sharpeners.

Summary

You might have been surprised to learn that less is more when it comes to lawn care in the heat of summer. (That is unless you have a warm-season species of grass in your lawn.)

Save your mowing and watering until the evening, mow a little longer, and try to limit the amount of use that one particular patch of grass gets to spread the load.

And, if things get a little brown, which they most likely will, fear not! Your grass will recover and return to its lush green state as soon as the cooler temperatures and rains of fall arrive.

Thank you for reading and as always, feel free to share your thoughts in the comments section below, I love hearing from you!

Andy Gibson

My name's Gibson. Andy Gibson. I like to think of myself as the Bond of the backyard, that is if yard work ever became sexy. I write about everything about indoor and outdoor gardening and the dread-it-but-still-need-to-do-it chores around the yard, like cleaning out the gutter guards.

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