Brown Patch in Cool Season Grasses

Fescue grass is the primary choice when it comes to a “shade” grass here in Oklahoma. While it can maintain its green color all year, it does come with some problems. One such problem that is present right now is a common turf disease called brown patch. Brown patch is caused by the fungus Rhizoctonia solani. It can present itself as circular or irregular patches in the lawn that are brown or bronze. Leaf blades may display lesions that appear tan, with a dark border around them.  

So what can be done about it?

First of all, the proper timing of nitrogen fertilization of fescue grass is important. Fescue does not need to be fertilized with a high nitrogen fertilizer in the summer. Save that for the spring and fall.

Watering is one of the biggest factors that you can control as a homeowner to help with the prevention and severity of brown patch disease. Watering deeply and infrequently is vital when it comes to turfgrass health. Reducing long periods of leaf wetness will help lessen the severity. Watering in the morning is best, as this allows the turf to dry during the day. It is not recommended to water in the evening, as this can lead to the grass staying wet all through the night, which is what Rhizoctonia would prefer.

Airflow is also important to help prevent the development of brown patch. Airflow will help with drying the grass leaves, so if you are able to reduce any obstacles or overgrown vegetation in the area, do so!

To help prevent brown patch, we recommend fungicide applications be applied when the conditions become favorable for brown patch development, which typically means later parts of the spring going into the summer. Curative applications can be done to help slow or stop the severity of brown patch, but we would recommend getting on a yearly preventative program.

If you have any concerns with your turf, please give us a call!