Louisiana has a humid subtropical climate with mild winters. However, every few years, winter temperatures will reach below 55 degrees Fahrenheit for extended periods and even below freezing — lower than 32 degrees Fahrenheit — for short periods. In northern Louisiana, icy precipitation is more likely than southern Louisiana. Depending on the temperature and temperature duration, turfgrass can be injured. This injury is typically not visible during the cool periods but becomes visible in spring when patches of dead turfgrass are surrounded by green and growing turfgrass. Understanding the causes of winter injury can help homeowners select more cold-tolerant species and develop management strategies to decrease winter injury incidence.
Warm-season turfgrasses are most susceptible to chill (32 to 50 degrees Fahrenheit) or freeze (below 32 degrees Fahrenheit) injury prior to acclimation in the fall or just after exiting dormancy in late winter or early spring. As the hours of daylight and temperatures decrease in fall, plants receive environmental cues as signals of changes in season that lead to complex reactions occurring in the plant. This period of acclimation is extremely important in preparing the plant for survival during unsuitable growing conditions. For warm-season plants, growth slows, energy reserves are funneled downward in the plant and dormancy can be induced. If severe cool temperatures suddenly occur before the plant is acclimated, there is less tolerance to winter injury. This is similar to what happens during late winter or early spring when the turfgrass is exiting dormancy and resuming growth. Stored energy is converted for use by the turfgrass to grow leaves and roots. These new tissues are tender and more prone to environmental stresses such as cool temperatures. Optimal temperatures for warm-season turfgrass shoot growth are 80 to 95 degrees Fahrenheit.
|Turfgrass dormant||Turfgrass dormant||Turfgrass active growth season||Turfgrass active growth season||Turfgrass active growth season||Turfgrass active growth season||Turfgrass active growth season||Turfgrass active growth season||Turfgrass active growth season||Turfgrass active growth season||Turfgrass dormant||Turfgrass dormant|
Semi-dormant warm-season turfgrass
Frost injury to warm-season turfgrass
Warm-season turfgrass species do not have the same cold tolerance as cool-season turfgrass species. The cold tolerance description in the table is relative based on areas that have suitable environmental conditions for growing warm-season turfgrass species as perennial plants. Zoysiagrass has the highest cold tolerance, followed by bermudagrass. Centipedegrass is typically more cold tolerant than St. Augustinegrass. Differences in cold tolerance can exist between cultivars of a species. Please consult your local extension agent if you have further questions concerning winter injury. As a general rule of thumb, warm-season turfgrasses that have rhizomes tend to have greater cold tolerance.
|Turfgrass Species||Cold Tolerance|
|Bermudagrass||Medium to excellent|