At what temperature does grass start dying?

Answered by Phillip Nicastro

Keep an Eye on Soil Temperatures: Root growth is heavily stunted when the top inch of soil reaches 75°F, and if soil reaches 90°F, roots near the surface can die.

When it comes to the temperature at which grass starts dying, it’s important to consider both air temperature and soil temperature. Grass is a resilient plant, but extreme temperatures can have a significant impact on its health and survival.

Air temperature plays a crucial role in determining the overall health of grass. Generally, cool-season grasses, such as Kentucky bluegrass and fescue, thrive in temperatures between 60°F and 75°F. These grasses can tolerate temperatures as low as 40°F and as high as 85°F, but prolonged exposure to extreme heat or cold can lead to damage and potential death.

In hot summer months, when temperatures frequently soar above 85°F, cool-season grasses can struggle to survive. The heat stress can cause the grass blades to turn brown and eventually die off. However, the grass’s root system remains dormant and can recover once temperatures cool down.

Soil temperature is another critical factor to consider when determining the health of grass. The top inch of soil is particularly important because it directly affects the roots, which are responsible for absorbing nutrients and water. When the top inch of soil reaches temperatures of around 75°F, root growth becomes heavily stunted. This means that the grass’s ability to take up essential resources for growth and survival is significantly impaired.

Furthermore, if the soil temperature reaches levels of around 90°F, roots near the surface can die. This can have a devastating impact on the grass’s overall health and ability to recover. It’s crucial to monitor soil temperatures, especially during hot summer days, to ensure the grass is not exposed to temperatures that can be detrimental to its survival.

To measure soil temperature, you can use a soil thermometer inserted into the ground at the desired depth. It’s advisable to take readings at different times of the day to get a comprehensive understanding of the temperature fluctuations throughout the day.

In my personal experience, I have seen the effects of high soil temperatures on grass firsthand. During a particularly hot summer, my lawn started to show signs of distress. The grass blades turned brown and brittle, and despite watering it regularly, the lawn’s health continued to decline. Upon checking the soil temperature, I discovered that the top inch of soil had reached temperatures above 90°F. This explained the poor condition of the grass and highlighted the importance of monitoring soil temperatures to prevent damage and promote healthy growth.

Grass can start dying when exposed to extreme temperatures. While cool-season grasses can tolerate temperatures between 40°F and 85°F, prolonged exposure to temperatures above this range can cause damage and even death. Additionally, soil temperature is a crucial factor to consider, with root growth being heavily stunted at around 75°F and roots near the surface dying at around 90°F. Monitoring both air and soil temperatures is essential to ensure the health and survival of grass.