Knowledgebase
Lawn problem #873653
Asked June 18, 2024, 3:56 PM EDT
Hennepin County Minnesota
Expert Response
Thanks for your question.
It appears that you have had this browning for a few years. In this particular area, when does the browning occur during the season? To put it another way, does this area start out green early in the season (May)? If so, when during the season does the browning occur (August)? The most likely possibility is a fungal disease. Have you even (or your lawn care company) applied a fungicide to your yard?
Besides getting back to us with answers to these questions, see the following that deal with lawn fungal diseases:
https://apps.extension.umn.edu/garden/diagnose/plant/turf/circular.html
https://ipm.ucanr.edu/agriculture/turfgrass/fusarium-blight/ - gsc.tab=0
After looking at these sites, please get back to us with your thoughts.
As I said, I suspect that we are dealing with a fungal turf disease. If you really want to get to the bottom of things, you may want to consider sending a sample of your turf into a plant diagnostic laboratory for an exact identification of the causative agent. After receiving further thoughts and information from you, this possibility will be addressed.
Thanks for consulting with us. Good luck.
Thanks for getting back.
Because of various climatic events, we have been receiving several questions regarding turf problems caused by these events. I now believe that these are not involved for your yard. Rather, I think there is a fungal cause. I say this for the following reasons:
1). If the brown grass in your yard was due to something environmental, I would expect this to occur in different places in different years. Always seeing this browning in the same area each year is consistent with a fungal infection.
2). If there were environmental factors in play, this should not lead to increased spreading of this problem in succeeding years. You would expect this if there was a fungal cause.
3). Fungal infections normally only do damage to grass blades but not to grass roots. For this reason, you keep seeing grass reappearing in the affected area year after year. Environmental causes often kill the grass completely so that it does not reappear.
Some other thoughts:
1). Aeration is not a factor. While this is important for overall turf quality, its lack would not explain the browning turf.
2). Applying a fungicide this fall may or may not be effective. Contrary to common belief, fungicides DO NOT kill fungi. Rather they just prevent fungal spores from germinating. In other words, applying a fungicide to brown turf would not be expected to lead to a restoration of green grass. Rather the fungicide would only prevent the brown areas from expanding.
3). For fungicides to be effective, they must be applied at times of maximum spore germination. Some fungal species show spore germination in the spring, and other species have spore germination in the fall. Knowing the exact fungal species causing the turf problem is an essential part of solving the problem.
In short, if you really want to deal with these brown turf areas, some type of diagnostic analysis must now be done. The Turfgrass Diagnostic Clinic at the University of Wisconsin is renowned for its ability to determine the cause of fungal problems such as you are experiencing and to suggest remedial measures. The cost is nominal. I believe that it is about $20 per submitted sample. I strongly urge you to contact them and send them samples of your turf. See:
After looking at this site, give them a call and describe the turf problems you are having. They will provide you guidance in the submission of samples. They have a fast turnaround time. If a fall fungicide application is needed, there still should be adequate time to do this.
If you do this diagnostic, please get back to me after your results are received so that implementation steps can be determined.
Good luck. Thanks for consulting us.
