When it’s time for the last cutting of your lawn, how low should you cut? Your area's winter snowcover should help you decide whether to cut it short or leave it long.
If you live in a heavy snow area, cut the grass to about 1.5 inches in fall to prevent it from matting down beneath the snow and forming a haven for the snow mold fungus.
In areas with little snowcover, grass dries out and the crowns may be injured from a lack of insulation. In those areas, leave the grass long over the winter to help protect the crowns from drying out.
The two biggest winter problems with lawns on the northern plains are snow mold and dehydration.
In areas where the snow lies all winter long, lawns suffer from snow mold. This fungus that lives beneath the snow causes grass to die out in patches. While snow mold is rarely a severe problem on bluegrasses, it can cause concern in spring, when the dead patches look horrible.
The precise time for the final lawn fertilizer application of the season also varies from place to place, but fertilizing around Columbus Day (after the last mowing but about four weeks before the soil freezes) is a good rule of thumb. Your lawn will green faster in spring if you remember the fall application.