Summertime is the season of fun in the sun. But chances are your lawn doesn’t share that same feeling. The hot, dry days of summer can take a huge toll on turf grass. This means that during the summer lawn care tasks become especially important to maintaining the health and and appearance of your grass.
Remember that summer is also when we demand the most from our lawns. It’s warm and everyone wants to be outside. This extra foot traffic from kids, pets, and (if I have anything to say about it) tipsy grown ups firing up the barbeque all put a strain on already stressed grasses.
And if you’re like me and want your lawn to look its best when you use it most, you need to step up your game to maintain that show-stopping deep green color.
Today, I’ll talk about how to help your grass withstand the harsh heat of summer, keeping it healthy (and looking great) so you can make the most of your yard.
Let’s start by briefly touching upon the two types of grass we have here in the U.S. and how they grow.
The Two Grass Categories: Cool-Season and Warm-Season Grasses
There are many types of lawn grasses, but they’re organized into two main categories: cool-season and warm-season grasses.
If you live in the northern or southern part of the United States, it will be immediately obvious by looking at the map below what kind of grass you have in your lawn.
But if you’re in the transitional zone you still have one of these grass types – it’s just that you live in a part of the country where either type of grass can grow.
The specific type of grass you have in your lawn can be determined quickly by thinking about when it looks best (if it looks best in spring/fall it’s cool season … if it looks best in summer it’s a warm season grass lawn).
About Cool Season Grasses
Cool-season grasses grow in the northern regions of the United States, in areas like New England or the Pacific Northwest. Examples include Fescues, Kentucky Bluegrass, and Perennial Ryegrass.
As their name implies, these grasses prefer cooler temperatures. Cool-season grasses hit their peak growing range at 60-degrees Fahrenheit.
They struggle during the heat and drought, and without proper summer lawn care efforts, they’ll go dormant and look brown and crispy when you want to use your lawn most.
Warm-season grasses prefer the warmer, southern regions of the country. Some varieties are adapted to humid air, like St. Augustine grass. However, others can thrive in dry climates, like Bermudagrass.
Unlike cool-season grasses, warm-season grasses prefer temperatures in the 70s, with a few varieties preferring it as high as 80-degrees Fahrenheit.
But when temps climb beyond 80-degrees, even a warm-season grass may struggle to grow and fade in color, so you’ve still got work to do if you want to keep it green and healthy looking.
About the Natural Dormant Periods of Lawn Grass
While dormancy is a natural part of how turfgrass has adapted to survive, many of us like to keep our lawns looking fresh, green, and inviting through the summer.
When you understand when (and why) grass goes dormant during the dog days of summer you’ll be able to identify warning signs and act proactively to keep up with summer stress.
I’ll try to provide some actionable tips and guidance for you in this article, breaking down your action plan into three sections:
- Early Summer,
- Mid-Summer, and
- Late Summer.
Early Summer Lawn Care
You fertilize your lawn in spring and work hard to get your lawn grown in healthy and strong. Summertime is about keeping your lawn going strong.
Early in the summer, there are a few things you can do to develop your lawn’s natural systems enough to be strong.
Let Your Grass Grow Higher
Early in the summer, you need to begin letting your grass blades grow a bit more by adjusting your lawn mower height setting.
Taller grass grows deeper root systems, which improves their water access and drought tolerance.
There’s always water in the soil, but the hot sun of summer and infrequent rainfall dries out the surface of your yard. By encouraging your lawn to grow deeper roots during the transition from spring to summer, your grass can access more water and nutrients in the soil than many other, competing grasses.
Furthermore, taller grasses shade the soil, protecting it from the sun. That keeps the soil moist longer, lowering the need to water.
Every grass has a different ideal height for mowing, but I recommend that you keep your lawn mowed as high as you are comfortable with throughout the summer.
Generally, cool-season grasses should be grown to around 4 inches at this time of year. Warm-season grasses, on the other hand, should be grown to around 3 inches.
Make sure not to mow more than 1/3 the height of the grass blade in one mowing session. If you take more, it will put too much stress on your grass.
I also suggest that you leave your grass clippings on your lawn to decay as a fertilizer if you have a mulching mower. This adds some nitrogen into your lawn while also keeping your lawn’s moisture levels optimal with some natural mulch.
Fertilize Your Lawn Well in Advance
It’s important to fertilize your lawn well before the heat and drought of the summer season sets in.
Apply fertilizer when your grass is beginning to grow for the season, that way it will grow in strong and develop its robust root system more quickly.
For cool-season grasses, this is early in the spring, usually in late March or early April. Don’t apply fertilizer in the heat of summer.
Warm-season grasses can be fertilized in April or May.
The best rule of thumb as to when to fertilize is based on your seasonal temperatures.
Cool-season grasses prefer temperatures in the 60s, which is when it’s best to apply fertilizer. For warm-season grasses, this is in the 70-degrees range, as that is their preferred season.
Best Fertilizer to Use in Late Spring or Early Summer
Choose a fertilizer that is designed to strengthen your lawn and prepare it for summer, usually something high in nitrogen, and with sufficient potassium (which helps your grass handle extreme temperature swings).
These are the first and third number in the N-P-K ratio you’ll find on the front of any bag of fertilizer.
I recommend PGF 16-0-8 fertilizer with Humic Acid from The Andersons as an excellent late spring / early summer fertilizer.
It has the perfect mix of nutrients to support your lawn and set it up for excellent performance over the summer.
I also like that it is a product that can be safely applied in states that restrict the use of fertilizers with phosphorus.
You can order it online from Amazon, or take 10% off with code LAWNCHICK when you order directly from the manufacturer right here.
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Be extremely careful to not apply too much fertilizer. This can backfire on you and can even kill your grass.
It’s a balancing act to apply the proper amounts to your lawn. Too much fertilizer will “burn” your lawn, which kills it by overloading nutrients.
Warm-season grasses can benefit from a second application of fertilizer in mid-summer. However, this should be avoided for cool-season grasses, which you should fertilize twice early in the season (early spring and late spring).
Treat Your Lawn for Weeds and Pests
Early in the summer is also when weeds and pests start to establish themselves in your lawn. It’s a lot easier to preemptively treat this issue with a good pre-emergent herbicide in spring instead of trying to battle annual weeds in the heat of summer.
As far as pests that can do damage in summer and fall, apply a grub control or insecticide treatment to your lawn to stop this issue from growing. Apply it per the product directions.
You can take the chemical route or a more natural one, like using milky spore or beneficial nematodes to kill grubs.
Make a point of pulling weeds as you see them. The sooner and quicker you pull weeds, the less likely they’ll seed and become widespread in your yard.
Another option is to use a post-emergent herbicide / selective lawn weed killer that targets broadleaf weeds.
This will usually be safe for your grass in summer, but it can cause harm if you use it too often or don’t use the manufacturer’s recommended mixing ratio or application rate.
Mid-Summer Lawn Care
As mid-summer approaches, temperatures will be increasing and putting more stress on your grass.
You should have ensured that your lawn has a strong foundation, but you can make that even stronger with the right moves now.
Maintain Your Water Levels
The high heat of summer will deplete your soil’s moisture, and irrigation is the best tool to combat this.
If you’ve taken the right steps through the spring and early summer, your lawn should already have a deep root system.
To further strengthen those roots, you should water deeply but less frequently. Avoid light daily irrigation in favor of watering for longer periods with a day or two in between.
Water your lawn deeply twice a week so that the water reaches 4 to 6 inches deep in your yard. You can apply a water meter or dig up a part of your soil using a trowel to test how well your water seeps into the soil.
Do this by pushing the trowel into the soil. A lot of resistance means there’s too little water, while no resistance means there’s too much water.
Get a Handle on Your Sprinkler Output
You can also use small rain or sprinkler gauges strategically placed in your yard to keep tabs on how much rain you receive and how much irrigation you’re putting on to your lawn.
I own and recommend this sprinkler gauge 10-pack from Sunday (12% off with code LAWNCHICK2023) as a good way to get a good understanding of your sprinkler coverage and how long you need to run your sprinkler or irrigation system to get 1″ of water on the lawn.
Water your lawn early in the morning, between 6:00 am and 10:00 am. The earlier the better.
You want to water when it’s cool enough that the water won’t just evaporate. That gives your lawn time to absorb the moisture and you waste less of it.
Watering too late in the day will lead to a lot of it evaporating before it can even land on your yard, which is a big no-no when water is such a precious resource and in short supply in so many parts of the world.
Watering too late in the day or during the evening will make your grass too moist overnight. This can lead to fungus issues and disease.
Late Summer Lawn Care
The high heat of late summer makes watering incredibly important.
However, if your lawn has gone dormant because of an inability to water regularly, I recommend just allowing it to remain dormant until the fall.
It’s natural, and I believe it’s best to let your turf do what it needs to do to survive. If it needs to go dormant, you may do more harm than good by trying to wake it up during a period of high stress.
But as you begin to look toward recovery during late summer and early autumn, there are steps you should take to get your lawn into shape for the winter.
Aerate Your Lawn
Use a core aerator to break up and loosen compacted soil. You can rent a mechanical aerator or get a smaller, manual product like this one on Amazon.
If your lawn is large enough, it may be worth it to hire a landscaping team to do this for you. Compare costs before doing so.
In some cases, hiring a landscaper won’t be much more expensive than renting. These are heavy machines so for many homeowners just paying a pro is a good choice and worth the extra money.
Aeration allows more oxygen into the soil, helps water penetrate to the roots.
It improves the health of the soil during the critical late-season heat and gives your lawn the soil structure it needs to recover when you apply your fall lawn fertilizer.
Get a Jump on Overseeding
If your lawn has bare patches or seems thin, overseeding when you aerate in late summer or early fall will help it fill out. If you’re using a cool-season grass, you can wait until the weather starts to cool.
Overseeding is the process of laying excess grass seed on your lawn to let it grow in stronger to crowd out weeds.
Overseeding in the fall lets the grass grow in stronger to be more durable during the heat of next summer.
I have a free grass seed calculator to help you determine the perfect amount of seed to order for overseeding your yard.
Don’t Neglect Lawn Care in Summer
As you manage your lawn through the summer heat, it’s important to pay attention to the weather. Adjust your lawn care treatment based on how hot it will be or how much rain is in the forecast.
A hotter week will need more water, while a wet week will allow you to cut back on irrigation.
If you can limit foot traffic on your lawn, during the hottest, driest periods of the summer you’ll notice a pretty big difference in how your lawn performs.
But don’t worry if you do struggle to keep your lawn looking good in the summer heat.
The grasses we use in our lawns have evolved to go dormant when they need to in order to survive in adverse conditions. If yours does this don’t sweat it!
Lawns are resilient and will bounce back in the fall as long as you give them the appropriate care and attention as they emerge from dormancy.