Winter effects linger on lawns: Unsightly mold and gnawed trees

Snow mold02
Snow mold is seen on the ground on Wednesday after a thick layer of snow and ice melted away in West St. Paul, Minn.
Andrew Krueger | MPR News

As the deep winter snow melted this spring, it left unsightly grey patches or fuzzy white mold across many lawns.  

“I have seen some pretty bad photos of snow mold,” said Julie Weisenhorn, a horticulture educator with the University of Minnesota Extension. “Snow mold grows on our turf grasses and this year because of the heavy snow and all the moisture that that brings, that has made snow mold worse.”

It might look bad, but snow mold is not likely to permanently damage the lawn.

A properly timed raking of the grass should remove the mold, lift the matted grass and let air circulate in the lawn.

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“You want to stay off of that lawn until it does have a chance to dry out,” said Weisenhorn. “We don't want people raking when it's wet because you'll end up pulling out your grass plants and then you'll really have a big seeding job on your hands.”

One way to reduce snow mold in the spring is to cut grass short late in the fall.

The deep snow this winter also gave rabbits the jump on many homeowners who are now seeing damaged trees and shrubs. 

Extension educators recommend putting wire mesh four feet tall around shrubs and trees to keep rabbits at bay. But this winter, the deep snow allowed rabbits to defeat the best efforts to protect tasty trees.

“I had damage to my glossy black chokeberry at chest height because the rabbits had enough snow that they could jump up on top of my air conditioning unit and nibble away at that plant,” said Weisenhorn.

Do those gnaw marks around the trunk or neatly clipped branches mean the end for trees and shrubs?

Weisenhorn advises waiting to make a judgment.

“I think by the time shrubs and trees start to start to leaf out you will know at that point if this branch is dead or not, or if this tree is dead or not,” she said. “If it's on a shrub, you can prune off the branch. If it's your tree and you're just seeing really poor leaf growth, it may be necessary to replace that tree.”

a tree with bark chewed away
A young fruit tree in Moorhead, Minn. shows damage by rabbits on Friday.
Dan Gunderson | MPR News

Weisenhorn said protecting plants from rabbits and deer requires starting early and keeping a watchful eye throughout the season. In addition to wire mesh around plants, she suggests starting to use repellents in the fall. Use several different kinds of repellents that taste and small bad to keep animals guessing, she said. 

And realize that sometimes the wildlife will win.

“They were here before we were, and as we expand, taking up farm fields and woodland areas with housing developments, we're going to have to learn to live with wildlife,” said Weisenhorn. “So, we need to adapt our gardening styles.”