Question of the Week
Last Spring I had powdery mildew on my front lawn which faces North. It only gets sunlight late in the afternoon. It stunted the growth of the grass but fortunately did not kill the grass. Is there anything I can do to prevent the powdery mildew from recurring next Spring?
What you may be seeing is snow mold. Snow mold is sometimes seen in the spring after the snow melts and is more common when heavy snow has fallen on unfrozen ground. There are two types of snow mold; gray snow mold (Typhula spp.) which usually only infects the grass blades and pink snow mold (Microdochium nivale) which can infect the crown and the roots of the grass as well as the foliage and can thus be more damaging. With the late winter and early spring snow storms we have had this year, snow mold may be more common this spring.
Snow mold (and powdery mildew for that matter) is generally not a serious problem and fungicide applications are not recommended. The normal recommendation is simply to lightly rake the area to allow the grass to dry more quickly. This also disrupts the growth of the fungi.
In most cases, the grass will slowly recover and green up - just a little slower than the rest of the lawn. Sometimes small patches of grass may be killed and these areas can be over-seeded and then top dressed with a thin layer of good quality compost.
If there is anything you can do to increase the amount of sun getting to the lawn such as the selective pruning of a few trees, this will also help with the problem of mildew on the grass.