Red Thread Fungus on Turf

We have a pretty nice lawn here at the Extension HQ in Jackson Park. However, we get problems just like everyone else. This year we have Red thread fungus causing dead patches in our lawn.

What Conditions Does Red Thread Fungus Like?

If you look closely at the pictures you can see 'red threads' on the grass leaves. These are fungal structures that are feeding on the grass. The fungus usually doesn't kill the grass plants. It just kills leaves.

The red thread fungus spreads rapidly when temperatures approach 70 degrees F and the weather is rainy. We have had plenty of cool wet weather this spring so I expect this problem will get worse. Sometimes the affected areas can be up to two feet across.

Control

Here in the Extension HQ lawn, I'll just let this red thread problem go and let nature take its course. The fungus won't kill the grass so I can live with some brown spots for a while. Once the weather heats up closer to 80 degrees F, the fungus will shut down. Eventually the grass will recover.

However, some people have a lower tolerance for lawn damage than I do. Golf courses, estates, commercial properties and other high profile areas might want to control the fungus. In that case you can spray fungicides to stop the spread. Learn about what fungicides to use here.