MINNEAPOLIS -- Snow mold was a huge problem last spring. The weather played a huge part with a perfect "storm" for snow mold unfolding all winter long.
Snow that fell early in the season on the ground that wasn't frozen. Many lawns still having leaves and debris that wasn't able to be picked up and snow pack that lasted for over 100 days in many areas.
Bob Mugaas a extension educator for the University of Minnesota in turfgrass management explains the issue and the autumn/early winter lawn care tips that you can use to prevent another bumper crop for snow mold.
RELATED: Information on snow mold infestation
RELATED: Information on snow mold
Following are some late season lawn care tips that can help reduce the severity of snowmold infestation in home lawns next spring:
1. During the last 2 or 3 mowings of the year, gradually reduce the lawn height down to about two inches. Regular mowing throughout the fall period at gradually shorter heights prevents excessively long grass from developing. It's this long grass that, when matted over under a snow cover, provides increased habitat for the snowmold fungi to survive and grow. In turn, this can increase severity of snow mold infestation next spring.
2. Small amounts of fall leaves (less than 2 - 3 inches deep) can usually be ground up sufficiently through mowing. When finished mowing, there should be little evidence that fall leaves were present on the lawn surface and the lawn should look as though it has been thoroughly raked. As these chopped up leaves further decompose they become a source of organic matter for the lawn as well as provide a small amount of nutrients for grass and other plants to use. Any visibly remaining clumps of leaves, chopped up or not, leaves should be raked up, removed and added to the compost pile or used as a mulch elsewhere in the landscape.
3. Unraked leaves or those not chopped up through mowing can themselves contribute to increased snowmold. This is not because the snowmold fungi feed directly on the dead leaves. Rather, they can form an additional canopy over the grass plants thereby increasing the amount of favorable habitat for the snowmold fungi. Besides increased snowmold concerns, a thick layer of leaves left on the lawn over winter can directly result in some dieback and thinning of the grass plants. All this is to say that removing or at least reducing the amount of tree leaves remaining on the lawn before winter arrives is a good lawn care practice.
4. Avoid encouraging lush, tender grass growth with too much nitrogen fertilizer from about mid-September to mid October. Nitrogen rich grass foliage encourages increased snowmold growth during favorable winter conditions. The best time to have applied some additional nitrogen would have been around Labor Day to about the middle of September. New research at the University of Minnesota has cast doubt on the usefulness of the very late October to early November application of nitrogen fertilizer as was previously recommended. Hence, getting nitrogen down around Labor Day is a better practice as the nitrogen is more efficiently taken up by the grass plant compared to later in the season.
5. Even under the best preparation, snow mold severity will be greater when snow arrives on unfrozen lawns and the snow cover remains in-tact throughout the winter months. In most years, snowmold fungi develop rapidly during the cold wet conditions associated with spring snow melt. However, as environmental conditions at the lawn/snow pack interface can change rapidly during that period, the severity of snowmold is usually less compared to the previously mentioned situation.
Thanks to Bob for all of his help. Good Luck getting all those leaves picked up and grass cut short!
Belinda & Bobby
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