CHESTERFIELD, Mo. – This is the time of year for turf diseases to occur in the St. Louis area. Those diseases love hot, humid, and wet conditions. So far, the weather has been hot and dry, but the recent rain may have had an impact.

“The main grasses in the St. Louis area are going to be tall fescue or bluegrass,” said Craig Calhoun, a turf manager with Ryan Lawn and Tree. “So, we’re seeing some brown patch on the fescue as well as some dollar spot on the bluegrass right now. The rain yesterday that we had, I think we can expect to see some more start to pop up over the next week.”

The majority of brown grass seen around town is dormant grass due to the drought-like conditions. It could be a different issue for lawns that are getting plenty of water but still having some brown spots develop.

“If you’re watering properly more than likely, it’s going to be disease. When you see those spots, we recommend you call a professional,” said Calhoun. “You can spray a fungicide on the lawn to stop all activity on the disease as well as prevent it.”

“Generally, the legions on the turf grass plant will give us an identification of what disease it is as well as if it’s going dormant,” said Calhoun. “With brown patch, you’ll have more circles throughout the yard, spread out unevenly in the yard. And dollar spot will generally be about the size of a bowling ball, and you’ll just see perfect circles throughout the yard. Drought stress, it’s just all over.”

In a few weeks, another disease may impact area lawns if we get some rain.

“Pythium is a disease that we’ll start to see in August. You’ll need to prevent it,” said Calhoun. “Once a yard gets Pythium what will happen is it’ll kill the grass plant. So those areas will have to be reseeded.”

The summer has been tough on turf.

“There will be some seeding that has to take place in yards whether it’s hit with disease or drought stress in September,” said Calhoun.

Calhoun said that with current weather, they recommend watering your yard about an inch and a half a week. He said to mow on the highest setting and make sure you have a sharp blade.