There are several causes of brown spots in summer lawns. Three of the most common causes are drought, grub damage and disease.
Drought:This is perhaps the most common cause of brown grass in the summer. If you want your lawn to stay nice and green, you must ensure your lawn gets one to two inches of water per week. Using a rain gauge will help you determine when your lawn has received enough water. Another guideline is to water when the lawn starts to take on a bluish tinge, or when you can see
your footprints in the grass after you have walked across the lawn. Drought damage will cause all or part of your lawn to turn tan to brown. If enough time passes without enough water, all or part of your lawn will die and need to be reseeded in the fall.
Grub Damage:Another common cause of brown spots in our area is grub damage. The easiest way to identify grub damage is to get down and examine the brown spots. If you the affected area pulls up easily, like a carpet, then grubs are the likely culprit. You may even catch some grubs still feeding in the area. Your local garden center will have products to prevent and control grubs.
Disease: Lawn disease can also cause brown spots in lawns. Most lawn diseases are caused by our hot, humid summer days and nights. The most common disease active in our area is Brown Patch. The first signs of Brown Patch are thin patches of light brown grass that are roughly circular in shape. Other times, the disease skips the circular phase and large areas of the lawn will turn thin and brown. Once again, your local garden center will have products to control disease, although the products with the longest protection period are only available to commercial pesticide applicators.
If you decide not to treat, the grass may grow out of the problem. However, this is risky as just as often the grass will die and need to be reseeded in the fall. If your lawn was planted last fall (2008) I strongly recommend treating, as these young seedlings are hit hardest by disease.
Brown spots are ubiquitous in the summer, but what are YOUR lawn concerns? Leave a comment below if you have questions and I will get an answer for you.