On greens with mixed annual bluegrass/bentgrass populations, the bentgrass usually will colonize the center of patches of affected annual bluegrass, creating a ring-shaped appearance. This is the easiest way to identify summer patch.
Since summer patch is a root disease, cultural practices that promote good root growth will aid in reducing disease severity. Increased aeration and improved drainage on compacted and poorly-drained soils will alleviate some root inhibition. Here are a few pointers:
- Avoid light, frequent applications of water.
- Avoid heavy nitrogen fertility, especially in the spring.
- Use slow release sources of nitrogen fertilizer.
- Reduce thatch when the layer is over ½ inches thick.
- Core aerate compacted soils in the fall, and if necessary, repeat core aeration in the spring.
A control product such as Bayer Fungus Control for Lawns will also help restore your lawn's natural beauty.