Learn Your Lawn: Gray Leaf Spot

What Is Gray Leaf Spot?

Gray Leaf Spot is a fungal disease that tends to affect warm- season grasses, such as Bermuda, Zoysia, St. Augustine, and Tall Fescue, in the warm and humid regions of the United States. The disease appears on the leaf blades of the turf as circular or oval-shaped, tan-colored lesions with brown or purplish borders. In severe cases, lesions can develop on leaf sheaths and stems and the leaves will wither and die. As the disease progresses, the affected area will grow larger and the grass will begin to thin out, turn brown, and die, sometimes killing large areas of the lawn. Unless the disease is controlled, it can cause devastating damage.

How Can I Control Gray Leaf Spot In My Lawn? 

Gray Leaf Spot is very difficult to control, as it thrives in hot and humid weather conditions. In most cases, a change in the weather can help reduce the spread of this disease. You can also adjust your cultural practices to improve the health of the lawn and further limit the spread of the disease. However, depending on the size of the infestation and the scope of the damage, other forms of control may be necessary. 

A thick, healthy, well-maintained lawn is the best line of defense. Here’s how you can adjust your beneficial cultural practices to reduce the spread of Gray Leaf Spot: 

• Avoid Watering: Under normal circumstances, you should be watering each area of your lawn for 30-45 minutes, twice per week, in the early morning so the turf is dry by nightfall. However, you should avoid watering when the disease is active.

• Avoid Mowing: You should avoid mowing when the disease is active. If you do have to mow, make sure your mower blade is razor sharp, so that the blade does not fray the tips of the grass, spreading the disease. Maintain a regular mowing schedule throughout the growing season. In general, you should keep your lawn between 2 1⁄2 and 3 1⁄2 inches high, but during the hottest weeks of summer, you may allow the grass to grow as high as 4 inches. Never remove more than 1/3 of the grass blade at each mowing 

• Fertilize Regularly: Regular applications of Weed Man’s specially formulated, slow-release granular fertilizer will help provide your lawn with adequate nutrients. These applications are timed specifically to avoid over fertilizing the lawn. 

• Core Aeration: Aerating your lawn can improve soil drainage and help reduce the likelihood of lawn diseases. This will also alleviate soil compaction and allow water and nutrients to penetrate deeper into the soil. 

Your local Weed Man professional may be able to offer other solutions and recommend the best form of treatment that is available to improve the conditions of your lawn.