I have dead brown patches in my lawn. I've eliminated all potential causes but "lawn patch," which is caused by a fungus. How do I prevent the further spread of the disease?
Ramsey County Minnesota
Our website is undergoing a renovation and still adding content, so here is a publications from our colleagues at University of Illinois: http://extension.illinois.edu/lawntalk/weeds/managing_patch_disease_in_lawns.cfm
Causes of lawn patch (summer patch, brown patch) include thatch (not common in most MN home lawns) and poor soil conditions. Lawns are commonly on compacted soils and core aerating soil (the mechanical removal of soil cores) will relieve compaction by increasing porosity in soil. It's important to do this in the fall - doing so in the spring can also promote weed seeds to germinate. Topdressing / overseeding after aerating will improve the seed-to-soil contact that is so important to good germination. Other reasons for patch are listed in this publication from U of IL.