Lawn drainage and fungal issue
I'm having trouble deciding what to do about this fungal issue. It has taken hold in a few of my lawns. The conditions are wet and stay wet without irrigation, so I think there must be poor drainage as well as being partially shaded. I thought about possibly using Eagle 20 fungicide to tackle the problem, but I am not sure. Also, are there any cultural type of things I can do to keep the lawn from being overly saturated with water? What is the name of this fungus?
The only effective cultural steps to prevent water standing or water logging in lawns is to either put in drainage tile (which is pretty destructive now) or to build up the level of the turf. Golf courses gradually add sand over the low or poorly drained spots until the turf has some drainage and better aeration. This is often a multiple year process since you can only add about .5-1 inch layer of sand each year. You can use a fungicide but with water staying on the surface of the soil, you will always lose some low spots to lack of aeration in the soil over winter. Top dressing with compost every year will also gradually improve the soil drainage but it is a pretty slow process. You can add 2-3 inches of compost each year.