What's Wrong with My Lawn?! Lawn Diseases Prominent this Year

The weather so far this year has been very conducive for diseases. Home gardeners are seeing brown patches form, white dusting in shady areas, and finding orange shoes after mowing.  Warm temperatures, frequent rains, and humid conditions create the perfect conditions for several different diseases to thrive.

Image of leaf spot and melting-out
Leaf Spot and Melting Out  (1)

What to Look For

The most common issues being seen across the state include these diseases: 

rust on shoes
Rust will leave shoes orange after mowing  (2) 

Management

Fungicides are rarely needed for home lawns.  Most of these issues can be managed with good cultural practices, like watering in the morning and fertilizing appropriately.  Learn how to manage all these diseases in this article: 

How to Prevent Turfgrass Diseases

How to Recover

Powdery mildew on grass blades
Powdery mildew on grass blades  (3)

Any spots that die out can be reseeded in late August/early September.  More information can be found in this article: Overseeding a Lawn.

Watch how to fix dead patches in this video: Fixing Lawn Patches.

Fall is a great time for core aeration, which promotes healthy growing conditions.  Learn more in this article: Core Aeration of Lawns.

More Information

 Lawn and Turfgrass Resources for Iowa: Diseases.  



pythium on turfgrass
Pythium Blight  (4)
brown patch P. Sell, Bugwood-org
Brown Patch  (5)
Image of rust pustules on turf grass
Rust pustules on turf grass  (6)


Photo credits: 1: Iowa State University Plant and Insect Diagnostic Clinic; 2: Peter Landschoot, Penn State; 3:  Iowa State University Plant and Insect Diagnostic Clinic; 4:  Iowa State University Plant and Insect Diagnostic Clinic; 5: P. Sell, Bugwood.org; 6:  Iowa State University Plant and Insect Diagnostic Clinic

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on August 20, 2025. The information contained within may not be the most current and accurate depending on when it is accessed.