Late summer and fall is prime time for rust, a fungal disease of turf grass. It happens during warm, humid weather, and when the grass is stressed at the end of a long, hot summer. This fungus won’t kill your lawn, but it will make it more susceptible to other problems. But by improving the overall health of your grass, you can get rid of rust.
Dethatching and fertilizing with a high-nitrogen fertilizer will make your grass healthier. Don’t mow your grass shorter than 3 in. Rake up rust infected clippings and get them off the lawn. Water in the morning so leaf blades don’t stay wet. Once you’ve improved the condition of your lawn, the rust should disappear in a week or two. Dry fall weather will help too.
Having rust on your lawn once doesn’t mean you’ll have it again, but some grass cultivars are more susceptible than others. Check the bag when you buy grass seed to see if it’s a rust-resistant cultivar.