While the springtime temperatures in Indiana do not encourage turfgrass diseases, soon the daily temperatures will be approaching 90-degrees. If your lawn’s soil has too much nitrogen stored from spring fertility treatments, you could risk losing lots of turfgrass to disease pressure.
The only way to fight off disease at this point is to go into a cycle of spraying fungicides every two to three weeks. The other choice is to let the disease run its course and wipe out your lawn.
To combat this disease issue. Apply no more than 1 pound of Nitrogen per 1,000 sq, ft. by the first week of May. If you miss that application window and want to fertilize your lawn in late May. Reduce your nitrogen rate to ½ pound per 1000 sq. ft. As a general rule, with proper springtime fertility, you should not need to fertilize your lawn from June 1 to late August. Close to Labor Day, resume your fertility treatments starting at 1 pound of nitrogen per 1000 sq. ft. The early Fall is a good time to add a pound of potassium at 1 pound per 1000 sq, ft. too. This will help strengthen your root system and get your turf prepared for the long winter nap it will start in December!