Seeing brown spots? You’re not the only one.
What is Summer Patch?
Magnaporthe poae, better known as Summer Patch, has been hitting lawns all across Iowa leaving brown spots along the way. Summer patch primarily affects 2 – 5 years old Kentucky Blue Grass that was laid as sod.
So what are the signs?
+ Dull red, tan, or straw-colored grass in a frog-eye pattern
+ Dark brown or black roots
How do I get rid of Summer Patch?
There’s good news and bad news.
+ Good news: There are preventative fungicides that are labeled for summer patch.
+ Bad news: Once symptoms appear it’s too late for fungicides. There are combinations of fungicides containing chemicals demethylation inhibiting fungicides, and tropidurids, that help control summer patch, for example Disarm™, Headway™, and Armada™ contain both fungicides.
What can I do to prevent it?
+ Improving internal drainage through aeration can help. You can read more about aeration here.
+ Raising mow height during stress periods can help reduce disease.
+ Fungicide applications can begin in early spring and be repeated 2-3 times until mid-August.
+ If summer patch or necrotic ring spot is an annual problem, consider over-seeding resistant varieties, like Kentucky Blue Grass.
Want to learn more? Check out this informational handout from Iowa State.