The Impact of Heat on Your Lawn
High temperatures can cause cool-season grasses like tall fescue or Kentucky bluegrass to undergo photorespiration, a process that saps the plant’s energy even if there’s enough moisture in the soil. This makes these grasses particularly vulnerable during hot, dry spells. While they can go semi-dormant to survive drought, extended periods of heat and dryness can severely damage them.
Warm-season grasses, such as zoysiagrass, bermudagrass, centipedegrass, and St. Augustinegrass, generally handle heat better. However, without adequate soil moisture, even these grasses can start to brown. Zoysiagrass tends to brown faster than bermudagrass, but both have similar long-term drought tolerance. Initially, centipedegrass and St. Augustinegrass might cope due to their stolons, but they suffer more over time. Despite turning brown, these grasses can usually recover when favorable moisture levels return.
How to Water Your Lawn Effectively
Depending on your irrigation system and any current water restrictions, you have two options: maintain growth and green color with regular watering or irrigate just enough to ensure your turf survives by letting it go semi-dormant.
**Regular Watering**: Turf needs about 1 inch of water per week from rainfall or irrigation. In the heat of summer, it might need up to 2 inches per week if soil moisture is available. Watering at night, between 10:00 p.m. and 8:00 a.m., can improve efficiency, especially if you have low water pressure. Check your irrigation system for even distribution and use catch containers to measure the amount of water applied. Adjust your watering schedule based on the turf’s appearance, watering only when it starts to look bluish-gray in the heat of the day.
**Minimal Watering**: If you decide to conserve water, apply ½ inch of water every two to three weeks to keep the turf crowns hydrated. This won’t make the grass green, but it will help it survive. Avoid using herbicides and fertilizers until the drought passes and keep heavy traffic, including riding mowers, off the lawn to prevent further stress.
Remember, the specific needs of your lawn depend on the grass species, turf age, soil type, shade, maintenance practices, and traffic. By understanding these factors and adjusting your watering strategy, you can help your lawn survive and even thrive during drought conditions. Stay mindful of any water restrictions and prioritize the most stressed areas of your lawn for hand watering if necessary.
Keeping your lawn healthy during a drought is challenging, but with careful management, you can maintain its beauty and resilience. Happy gardening!
