Lawn Brown Patches May Be Summer Patch aka Fusarium

Pictures from reader concerning the brown patches
in her lawn

Q. I have some brown patches in the grass in my yard.  The sprinklers are working fine and the recent rains haven't made any difference.  This area was nice and green until about three weeks ago.  I'm hoping you may have some idea what is causing this and what I might do to resolve the problem.  The rest of the yard is fine.

A. Your lawn has, from the pictures you sent, what appears to be summer patch disease. This disease used to be called Fusarium patch in the old days. Some management techniques that you can try include mowing the lawn a bit shorter during the heat of the summer. 

            If you fertilize your lawn during the summer make sure you use half the amount recommended on the bag or less. Fertilize in the early morning hours only and make sure it is watered in immediately after the application. Foliar applications would be even better.

            Avoid watering the lawn anytime between late afternoon and early evening and about 2:00 AM. You can water any time after 2:00 AM but try to get it done before sunrise.

            Otherwise you will need to apply fungicides to your lawn that have been approved for controlling summer patch or Fusarium diseases. You can find this out by reading the label. Fungicides are best in preventing diseases from spreading not curing them after the disease has ravaged the lawn. Mark your calendar for next year and apply a fungicide anytime you see summer monsoons predicted.