Managing Heat and Drought Stress
Summer stress takes many forms. With record-breaking temperatures in parts of our geography this week, heat stress is inevitable. In this blog post, we’ll discuss both heat and drought stress and what you can do to manage both.
Heat and drought stress can occur independently or together. When you have high temperatures and low rainfall, the two threaten a double dose of stress to your grass—and you. Heat stress occurs alone when temperatures are high, but rainfall is not especially low. High rainfall and thunderstorms can occur during heat stress.
Drought stress is typically associated with weather conditions, but it can also be caused by a malfunctioning irrigation system. Additionally, low soil moisture can cause drought stress even with regular irrigation. Use a soil probe to determine how much water is actually available to the plant, and irrigate in the early morning for best results.
Turfgrass reacts to heat and drought stress by going into dormancy, a defense mechanism that helps the plant survive prolonged heat and drought. During dormancy, the plant shuts down all of its essential functions to preserve its crown and roots. Browning leaves are a sign that grass is entering dormancy. The plant can eventually turn entirely brown to conserve resources.
When turfgrass is in the process of going dormant, foot and tire traffic can crush the plant cells and cause the leaves to turn brown. In the case of tire traffic, brown tracks can be mistaken for fertilizer burn. Once the plant resumes growth, the brown tracks will disappear. It’s also important to remember that herbicides are less effective in heat and drought stress because they work best when weeds are actively growing.
A simple way to mitigate heat and drought stress is proper mowing practices. Use sharp blades and mow higher in high-stress conditions. Taller turfgrass conserves water and provides more shade to the soil. In the fall, core aeration can help the plant bounce back from summer stress, as can fertilization. For any areas that don’t survive the summer, fall overseeding will help fill in bare spots.
Contact your ATS rep with questions about managing heat and drought stress this summer.