Years ago, scientists took a soil sample from deep below the ice in Antarctica and found something: brown patch.
Brown patch is a fungus causing brown circles in your lawn during the hot humid months of summer. Why did they find it in Antarctica then? Because brown patch can remain dormant for many years. The reason you notice it now is because it has become active, the good news is we can control it!
What is Brown Patch?
Brown patch (Rhizoctonia solani) is a soil-living fungus which becomes active in humid months where temperatures reach the mid 80’s during the day, and mid to upper 70’s overnight.
Like the name would lead you to believe, brown patch causes a brownish discoloration of your turfgrass. More specifically, it starts out with lesions on the grass blades (shown here).
As brown patch develops, these lesions spread to cover the entire grass blade, causing thinning and matting of the turf. On shorter lawns, these patches may appear to have a "smoke ring" of dark gray around the outer edge.
Why Do I Have Brown Patch?
If your lawn is wet going into the evening, the moisture can encourage the growth of the brown patch fungi. In addition, this disease can be more severe in areas which have restricted air movement, such as between houses, fences, or plants.
How to Prevent Brown Patch
As previously stated, this particular turf disease will be most successful if your lawn is wet going into the evening and night. To prevent brown patch water your lawn in the early morning, preferably between 3:00am - 8:00am.
Proper airflow is also crucial to preventing brown patch. As previously stated, brown patch prefers moist areas; so if you increase airflow in troublesome areas, it will help to dry off your turfgrass. Do your best to increase circulation in these areas by removing unnecessary objects or foliage in your backyard. Also, a proper regiment of aeration will help to strengthen your lawn and increase airflow to the root zone.
Proper Mowing Goes a Long Way
The simplest thing to help your grass combat this, and any turf disease, is mowing your lawn properly. We recommend homeowners to:
- Sharpen mower blades: dull blades cause wounds through which disease may spread.
- Do not mow the lawn when it is wet.
- Mow at the proper height—lawns mowed at the mower’s highest setting stand up to stress better.
How to Control Brown Patch
At the point where you need to control an outbreak of brown patch, don’t reach for a control material right away, as we have a few natural alternatives for you to try first. First, take a rake and fluff your grass where the brown patch has occurred. This will help speed up the drying process, so the brown patch fungi can return to dormancy.
When fertilizing, use organic fertilizers to provide the right blend of nutrients to prevent disease.
Hopefully, brown patch won’t be a huge problem for you this year, but if it is, just remember—with a little patience and some perseverance, you can use these methods to coerce the brown patch fungi back into remission, and keep it there.