Protect your lawn from snow mold with these tips - East Idaho News
In the Garden

Protect your lawn from snow mold with these tips

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Last spring, I wrote about what to do if you have snow mold on your lawn. This fall, I would like to focus on things you can do now to reduce spring snow mold.

Snow mold is a common fungal disease in east Idaho lawns. All cool-season grasses are susceptible, some more than others.

Snow molds prefer cool temperatures and high humidity. Gray snow mold is the most common in eastern Idaho. The disease is most likely to develop when there is a snow fall before the ground freezes. The other contributing factor is the presence of lush, long grass blades.

The longer the grass is covered with snow the greater the opportunity for snow mold to develop. Since we do not have the ability to control when the snow comes, we need to focus on other activities that will reduce snow mold development. There are no homeowner-approved fungicides for snow mold control.


A late fall fertilizer application if very good for the lawn. Timing is critical for late fall application. This should be done after the lawn has gone dormant. You don’t want to apply it while the grass is still growing as that will encourage a flush of lush growth, which the fungus loves.

Pink Mold
Pink snow mold | William M. Brown Jr.,

In addition, the late application is very light. It should be applied at no more than a half pound of nitrogen per 1,000 square feet. For example, if you apply ammonium sulfate, which is 20 percent nitrogen, to a 2,000-square-foot lawn, you would apply tow-and-a-half pounds of ammonium sulfate per 1,000 square feet, or five pounds on the entire 2,000-square-foot lawn.


The last mowing of the lawn is the other thing you can control that will help reduce snow mold development.

The normal mower height for Kentucky bluegrass lawns is two-an-a-half to four inches. This is for summer. The other normal recommendation is to mulch the clippings back onto the lawn during the growing season. The very last mowing is different.

To reduce the incidence of snow mold you want to mow short and remove the clippings. The lawn should be mowed at about two inches. If the lawn has not been treated with a fall weed control, you can put the clippings in the compost pile, or on the flower beds. It is especially good to mix the lawn clippings with fallen leaves, then apply that to the beds or in the compost pile.

Be proactive this fall to reduce the chance for snow mold development.


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