It’s getting hot out there. And just like you need to lather yourself in sunscreen and drink plenty of water when you hit the golf course or sit out by the pool, your lawn needs some special considerations as it sits out in the hot weather
But your lawn’s summer needs depends on the type of grass and the climate where you live.
“Know what kind of grass you have is the first thing,” says Ron Meyer, agronomist and crop production agent with the Colorado State Extension Service in Phillips County.
If you have a sturdier grass such as buffalograss, your lawn will be a lot tougher and able to handle the drought and heat, needing less water and care than some thirstier species, such as Kentucky bluegrass.
Warm-season, or Southern, grasses, grow strong straight through the summer while cool-season, or Northern, grasses, grow fastest in the spring and fall.
Warm-season grasses, such as Zoysiagrass, St. Augustinegrass, centipede and Bermuda grow best when temperatures are in the 70s, while cool-season grasses, including fescue, bluegrass and rye, grow best about 10-20 degrees cooler, in the 60s, explains the Texas A&M Extension in a summer lawn care guide.
A map from the Lawn Institute shows that cool-season grasses grow best in the northern half of the country, while the southern half is split between a transition zone where it may be difficult to grow either type, and where warm-season grasses do best — the Deep South.
Some people compensate by growing warm-season grasses when conditions favor them and growing cool-season grasses when temperatures favor those types.
Summer lawn care is about maintenance, the Texas A&M guide says, as opposed to a spring lawn to establish the grass, summer is a time for keeping a healthy lawn while temperatures climb and lawn use is at its height.
Here are some lawn care tips to keep your summer lawn green and ready for whatever this summer throws at it.
Warm-season grasses grow on a simple curve: starting as temperatures warm up in February and March, warm-season grasses peak their growth in the midst of summer, around June and July, trailing off as temperatures cool back off.
Mow warm-season grasses high during the summer, between two and three inches, according to the Texas A&M guide, which also recommends mulching grass clippings to help keep moisture levels steady.
And as always, don’t cut more than one-third of the length of the grass in any single mowing.
Also, resist the urge to fertilize grass when it starts to look straggly in the summer, which can create a rush of new, tender growth that will struggle in the heat. It’s better to fertilize a month before the hot summer weather arrives or to wait until fall.
For cool-season, or Northern, grasses, growth peaks twice throughout the year, first as the weather warms in spring, peaking in April.
Then, as temperatures reach their height, cool-season grasses drop to dormancy around July, before peaking again in the fall, around October, when the days begin to cool off.
Dennis Patton, horticulture agent at the Johnson County, Kansas, Extension office, writes that cool-season grasses should also be mowed high during warm months — no shorter than 3 inches.
Grasses don’t have a stem, Meyer explained, they’re all leaves. So if you keep them at about 3 inches, the plants are able to photosynthesize easier and stay healthier.
And when you bring out the lawn mower, make sure the mower blades are nice and sharp for a clean and healthy cut. Dull blades on lawn mowers will rip and tear the grass blades.
Patton also says not to fertilize cool-season grasses in the summer heat, as it greatly increases the water demands on the grass and hampers its adaptability to high temperatures.
Here’s where the biggest difference in warm- and cool-season grasses lies. Meyer said when temperatures reach 85 degrees, the more heat-tolerant warm-season grass types need about 1 inch of water per week and cool-season grasses double that.
“Water is the big thing,” he said. If cool-season grasses don’t get enough water, they’ll go dormant.
Lawns need at the very least 1 inch of water per week, says Texas A&M. Use a rain gauge or some kind of straight-sided can — such as a small tuna can — to audit how much water your lawn is getting.
Meyer says a good rule of thumb is that if you get an inch of rain, take about five days off from watering. If you get less than that, lay off only for a few days.
Hot summer months can also bring droughts that add stress to lawns, and watering deeply and less frequently can lead to deep roots better able to tolerate periods of drought.
Texas A&M also recommends watering in the early morning to reduce evaporation and fungal growth, and says either water your lawn frequently or not at all.
“Don’t let your lawn go brown and dormant, then try to ‘water it back to life,’” the guide says. “If your lawn goes dormant in the summer, it should stay that way until fall — don’t worry, it should recover once the weather changes.”
When a real drought hits, the University of Florida’s Institute of Food and Agricultural Sciences recommends cutting grass when it’s dry to get the cleanest possible cuts.
In many cases, lawns can survive prolonged periods of drought if watered only once or twice a week, with only 1/2 to 3/4 of an inch of water each time, according to the Institute.
The warmer weather can also bring out certain types of pests, Meyer warns, especially June Beetles in his part of the country. The large brown adult beetles that can be seen flying around in the summer aren’t the ones doing the damage, though, that’s the larva, the white grub.
Grubs will eat at the root system and separate them from the leaves. If you see a brown spot in your lawn, grab the grass and pull. If it separates from the root and comes up pretty easily, you’ve got grubs and you’ll need to treat for them, he said.
It’s something Meyer gets plenty of questions about, and the best way he advised to fend off the insects is simply by keeping your lawn healthy, well-watered and properly fertilized.