My neighbor and I were chatting recently when I noticed his lawn had some dying spots. He thought it was lack of water and had cranked up the minutes on his irrigation controller.
My suspicion was a disease instead of under watering. During the summer months, Fescue turfgrass is susceptible to disease, especially in the hot inland climates of California. Heat and improper irrigation can create a warm, moist environment in which disease (Pythium Blight in particular) can thrive and spread.
Symptoms of my neighbor’s lawn:
- Dead spots did not look like a sprinkler pattern.
- Areas right next to the dying spots were bright green, healthy grass
- He said all his sprinklers were running fine.
- There were spots on the leaf blade rather than a wilting of the whole blade.
- Spray the damaged area and surrounding areas with a fungicide as soon as possible.
- Cut back irrigation minutes 10-20% and observe for several days. Adjust accordingly after that depending on visual quality of the grass.
- If you can, wait for cooler weather to replace dead spots in your Fescue lawn (October to May is preferred).
A general tip for determining if an area of established turf is getting enough water is to stick a screw driver in the ground in the affected area. If the soil is moist several hours after irrigation, likely it is getting enough water and instead you have a disease problem. If you have difficulty getting the screwdriver in the ground and the soil has no moisture, you likely have a bad sprinkler or poor uniformity between sprinklers or not running the station for enough minutes.
Note: Hybrid Bermuda and St. Augustine are resistant to disease so this blog is focused on Fescue turf.