When temperatures climb into the 90s or higher, your lawn goes into survival mode. Avoiding these common mistakes can help your grass stay healthier and recover more quickly when cooler weather returns.
When temperatures climb into the 90s and higher, your lawn goes into survival mode. Avoiding these common mistakes can help your grass stay healthier and recover more quickly when cooler weather returns.
Colorado lawns face extra stress because of intense sunshine, low humidity, and drying winds. To help your lawn survive:
1. Mowing Too Short (or even mowing at all, according to this helpful article about lawns and heat)
Scalping your lawn is one of the biggest mistakes during hot weather. Taller grass shades the soil, keeps roots cooler, and reduces water loss. Raise your mower to 3-4 inches for cool-season grasses like Kentucky bluegrass and tall fescue, and mow in the coolest part of the day - typically evening right before sunset to give the lawn the chance to adjust before tomorrow's heat, or between 5am and 9am when breezes or winds are light and evaporation is decreased.
2. Watering Too Lightly
A quick daily sprinkle encourages shallow roots that dry out quickly. Instead, water deeply and infrequently, applying enough water to moisten the soil 6-8 inches deep.
Use the Cycle and Soak Method to successfully water deeply
This method is especially helpful on compacted or clay soils common in many parts of Colorado.
3. Watering During the Hottest Part of the Day
Midday watering loses more moisture to evaporation. Water early in the morning, ideally between 5 a.m. and 9 a.m., when temperatures are cooler and winds are lighter.
4. Fertilizing During Extreme Heat - don't encourage growth during heat
Applying fertilizer during a heat wave can stimulate tender new growth when the lawn is already stressed. Wait until temperatures moderate before feeding cool-season lawns.
5. Letting the Lawn Turn Bone Dry (which is different from dormant)
Many cool-season grasses like Kentucky Bluegrass naturally go dormant during prolonged heat, but they still need occasional watering. A dormant lawn typically needs about ½ to 1 inch of water every 2-3 weeks to keep the crowns alive until cooler weather returns.
6. Mowing a Drought-Stressed Lawn - it's ok to skip mowing right now
If the grass has stopped growing or is severely stressed, skip mowing until it begins growing again. Walking on heat-stressed turf also increases damage.
7. Heavy Foot Traffic
Dry, stressed grass bruises and wears easily. Try to minimize foot traffic and move lawn furniture or play equipment occasionally to avoid concentrated wear.
8. Using Herbicides
Many herbicides can injure lawns during hot weather, especially when temperatures exceed the product's recommended range. Delay weed control until conditions are cooler unless the label specifically allows hot-weather applications.
9. Ignoring Sprinkler Coverage
Hot spots often result from uneven irrigation rather than a lack of water. Audit your sprinkler system to make sure every area is receiving adequate coverage.
10. Assuming Brown Means Dead
Cool-season lawns often turn brown and go dormant to conserve water during extreme heat. If the crowns remain alive, the lawn usually greens up once cooler temperatures and regular moisture return.
Colorado lawns face extra stress because of intense sunshine, low humidity, and drying winds. To help your lawn survive:
- Mow high (3–4 inches).
- Water deeply in the early morning.
- Leave grass clippings on the lawn to help conserve moisture.
- Delay fertilizing and weed control until temperatures cool.
- Consider allowing your lawn to go partially dormant during extended heat and drought rather than trying to keep it lush green.
1. Mowing Too Short (or even mowing at all, according to this helpful article about lawns and heat)
Scalping your lawn is one of the biggest mistakes during hot weather. Taller grass shades the soil, keeps roots cooler, and reduces water loss. Raise your mower to 3-4 inches for cool-season grasses like Kentucky bluegrass and tall fescue, and mow in the coolest part of the day - typically evening right before sunset to give the lawn the chance to adjust before tomorrow's heat, or between 5am and 9am when breezes or winds are light and evaporation is decreased.
2. Watering Too Lightly
A quick daily sprinkle encourages shallow roots that dry out quickly. Instead, water deeply and infrequently, applying enough water to moisten the soil 6-8 inches deep.
Use the Cycle and Soak Method to successfully water deeply
- Water for 10–15 minutes.
- Turn the sprinkler off for 15 - 30 minutes
- Water again for 10-15 minutes (make sure there is no runoff - if there is stop watering to let the water soak in)
- Repeat once more. Check depth of moisture in the lawn with a moisture meter. If it doens't register good moisture 6 inches down, repeat the cycle a third time.
This method is especially helpful on compacted or clay soils common in many parts of Colorado.
3. Watering During the Hottest Part of the Day
Midday watering loses more moisture to evaporation. Water early in the morning, ideally between 5 a.m. and 9 a.m., when temperatures are cooler and winds are lighter.
4. Fertilizing During Extreme Heat - don't encourage growth during heat
Applying fertilizer during a heat wave can stimulate tender new growth when the lawn is already stressed. Wait until temperatures moderate before feeding cool-season lawns.
5. Letting the Lawn Turn Bone Dry (which is different from dormant)
Many cool-season grasses like Kentucky Bluegrass naturally go dormant during prolonged heat, but they still need occasional watering. A dormant lawn typically needs about ½ to 1 inch of water every 2-3 weeks to keep the crowns alive until cooler weather returns.
6. Mowing a Drought-Stressed Lawn - it's ok to skip mowing right now
If the grass has stopped growing or is severely stressed, skip mowing until it begins growing again. Walking on heat-stressed turf also increases damage.
7. Heavy Foot Traffic
Dry, stressed grass bruises and wears easily. Try to minimize foot traffic and move lawn furniture or play equipment occasionally to avoid concentrated wear.
8. Using Herbicides
Many herbicides can injure lawns during hot weather, especially when temperatures exceed the product's recommended range. Delay weed control until conditions are cooler unless the label specifically allows hot-weather applications.
9. Ignoring Sprinkler Coverage
Hot spots often result from uneven irrigation rather than a lack of water. Audit your sprinkler system to make sure every area is receiving adequate coverage.
10. Assuming Brown Means Dead
Cool-season lawns often turn brown and go dormant to conserve water during extreme heat. If the crowns remain alive, the lawn usually greens up once cooler temperatures and regular moisture return.
During a heat wave, the goal is to reduce stress, not force growth. Deep, consistent watering, higher mowing, and minimizing lawn maintenance will help your turf weather the heat and recover more quickly when cooler temperatures return.