Causes of Large Patch Disease
If you see an area of your lawn that looks like it is dying this time of year, it’s most likely a disease called “large patch”.
The fungus infects the leaf area closest to the soil, eventually killing the leaf.
The disease is most likely to be observed from November through May when temperatures are below 80 degrees. It is normally not observed in the summer months. Infection is triggered by rainfall, excessive irrigation, or extended periods of high humidity resulting in the leaves being continuously wet for 48 hours or more.
To reduce your chance of developing this type of fungus, I recommend that you reduce your watering amounts to no more than once per week. With of the rain we’ve been having, your lawn is probably already moist… and adding more water is creating an environment that is perfect for fungus and other diseases.
Another thing that will reduce the amount of damage to your lawn this month is to stay off of your lawn whenever we do have a frost. Let the sun warm the grass first before walking on it if at all possible.