A lawn in summer heat is usually a brown lawn, but that doesn’t mean it has to be unhealthy or that it can’t rebound. Many people choose to let their grass brown up and return to green on cooler days. Whether you let this happen or fight to keep it green, use these tips to maintain healthy grass.
The Lawn in Heat Waves
In most of the U.S., lawns are made up of cool weather grasses. These include Kentucky bluegrass, fescue, and perennial rye grass. They grow best in temperatures between 60 and 75 degrees F. (16-24 C.).
When the hot days of July arrive, these grasses naturally go dormant. This means the lawn turns brown, which may be natural but is less than ideal for homeowners. You have two choices: let it brown and go dormant (it will green up again as the days cool) or try to keep it going.
Hot Weather Lawn Care Tips
Lawn care in hot weather is different from on cooler days. It’s important to treat your grass a bit more gently and to avoid doing too much:
- Cut long. When you cut your grass during hot days, keep it long. A good general rule is to never cut more than one-third of the grass height. By keeping it longer, you allow the grass to develop stronger roots and a greater tolerance to heat and drought stress.
- Sharpen mower blades. Dull blades only stress grass more by damaging it. When blades are sharp, the grass will heal more quickly from each cut.
- Avoid mowing. In fact, it’s even better to avoid cutting the grass at all for a lawn in extreme heat or during a drought. Shady patches may be growing more and can be cut more frequently.
- Water deeply but infrequently. Overwatering grass won’t help. It generally does better when soil is a little dry. During hot summer days, water your lawn deeply but not necessarily daily.
- Water in the morning. The heat of the day will evaporate water quickly, so water the lawn early in the morning. This will allow the soil and roots to soak up more.
- Don’t fertilize. Avoid using fertilizers during the hottest part of the summer. Grass uses a lot of energy at this time of year, more than it produces. Fertilizing diverts that much-needed energy into new growth. This can lead to unnecessary stress.
- Keep foot traffic minimal. For already stressed grass, foot traffic can cause damage. Keep people off the lawn while the heat persists.
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FAQs
Watering your lawn efficiently and at the right time is crucial during a heat wave. Water your lawn early in the morning when temperatures are lower and evaporation is minimal. It's best to water your lawn deeply but infrequently, which promotes deep root growth and makes the grass more resilient to heat stress.
How often should I water grass in 100 degree heat? ›
WATERING SCHEDULE
Deeper roots stay cooler and stronger to better protect your lawn and garden from heat stress. Allow a deep watering at least once per week, twice if the temperature exceeds 100 degrees or more for several days in a row.
Should you mow in 100 degree weather? ›
'As a general guideline, you want to avoid mowing your lawn in temperatures above 90°F,' says Ryan Farley, CEO of Lawn Starter.
What is the best fertilizer for grass in hot weather? ›
The best fertilizer for your grass in summer and all year round is Lebanon Turf's Humic Max 16-0-8. This lawn fertilizer improves the appearance of your lawn with 16% nitrogen with healthy amounts of potassium to boost nutrient uptake.
What temperature is too hot for grass? ›
Once temperatures reach 77 degrees, it becomes too hot for root growth, and root growth ceases. When temperatures reach 90 degrees, it becomes too hot for shoot growth and the grasses stop growing and begin to fall dormant, with the surface grass turning a brown hue.
Should I leave my grass long during a heat wave? ›
Don't Cut Your Grass too Short
It is important to know that some types of grass have different growth habitats and their ideal mowing height should be taken into consideration, such as cool-season grass and warm-season grass types. 3 to 4 inches is a good height to keep your lawn during a heatwave.
What grass is good for 100 degree heat? ›
Heat Tolerance
Bermudagrass is extremely heat tolerant — daytime temperatures of 95 to 100 degrees Fahrenheit are optimal. Pennington Bermudagrass yields dense, resilient, heat-tolerant lawns. Zoysia grass, Centipede grass and Bahiagrass also tolerate high heat very well.
How to keep grass green in 100 degree weather? ›
During scorching 100-degree weather, watering your lawn becomes crucial to prevent it from withering under the intense heat. To ensure optimal hydration, it is best to water your lawn during the early morning (5 a.m. – 10 a.m.).
Is it OK to water grass in 90 degree weather? ›
When is it too hot outside to water your grass? In temperatures over 90 degrees Fahrenheit, it's best to turn off your sprinklers during the day. Essentially, any water you apply to your grass evaporates into thin (hot) air without reaching the soil to support your lawn.
Is it bad to cut grass in extreme heat? ›
Mowing a lawn in the middle of a summer heatwave is one of the worst things you can do to it. When temperatures reach around 85 degrees, grass, like many other green plants, begins to suffer – especially cool-season grasses such as Kentucky bluegrass, perennial ryegrass, and fine fescues.
Often this is due to improper watering to keep your lawn healthy. Other signs and symptoms of heat stress include the following: Compacted lawns make it hard for moisture to reach the root and would greatly benefit from aeration. To check your lawn, you can take a knife or screwdriver and stab it into the lawn.
Is it better to keep grass long or short in hot weather? ›
Mower Height
A mowing height between 2.5 to 3 inches is best for most of the season, except during summer stresses when the lawn mowing height should be raised one-half inch to mow at 3 to 3.5 inches. Raising the mowing height provides more insulation from summer heat and reduces water loss from your soil.
Can you use Miracle-Gro in hot weather? ›
You should take a break from feeding your plants during a heat wave or drought. However, to prepare them for conditions that could cause heat stress, regularly give them Miracle-Gro® Water Soluble All Purpose Plant Food (following all label directions) so they're nice and strong before the unfortunate weather arrives.
When not to apply lawn fertilizer? ›
When Should You NOT Fertilize Your Lawn?
- Don't fertilize when it's winter or early spring. Your lawn needs an extended period to recover from the cold weather. ...
- Don't fertilize when it's raining. ...
- Avoid fertilizing your lawn in the sweltering heat. ...
- Don't fertilize without knowing your grass type.
During scorching 100-degree weather, watering your lawn becomes crucial to prevent it from withering under the intense heat. To ensure optimal hydration, it is best to water your lawn during the early morning (5 a.m. – 10 a.m.).
How to fix a heat stressed lawn? ›
- Time your watering. Water your lawn between 6am and 10am. ...
- Water the right amount. Water deep, always. ...
- Set your mower blades high. Set your mower blades on the highest level for your grass. ...
- Reduce lawn use. ...
- Rethink fertilizing.
- Know the symptoms of heat-related lawn damage. ...
- Learn about your grass's “rest period.” ...
- Keep an eye on the weather and water accordingly. ...
- Water in the morning to prevent evaporation. ...
- Skip the fertilizer treatment. ...
- Keep mowing, but leave your grass longer than usual. ...
- Set up a sprinkler system.
