Talk about weather shifts. There I am a few weeks ago with a foot of snow to shovel and two weeks later the afternoon temperatures are in the 50’s. A few days after that we are back to mid-30’s for the afternoon high.
It is exactly that kind of weather madness that causes garden writers to blah, blah, and more blah every fall threatening dire results if you don’t mulch everything in sight except maybe for the cat. It’s the fluctuation of soil temperature and water levels that caused plants to take a beating in the past month of cold, then very warm, then cold again.
Plants in Michigan would not survive unless they could handle having their roots get frozen to some degree each year. The issue is how fast do the soil temperatures change over a period of days? Plants going from frozen feet to sitting in melted soil in just a few days suffer considerable stress. Mulch either prevents that stress or at least eases it.
Established plants in the landscape are usually not your concern. You need to pay attention to what is happening to any tree, shrub, or perennial that was planted in just the past two years. Those are the plants particularly vulnerable to damage when soil temperatures rapidly shift up and down. In some cases, some of those newbies can be physically forced up out of the ground as those temperatures shift. If you catch the problem and push them back down into the soil, there is little to worry about. If they experience that heaving and then sit exposed until spring, you may lose the plant to dehydration.
If you did not mulch those plants last fall with a two to three inch layer of organic mulch such as chopped leaves or shredded bark, take a minute to feel guilty and then get some mulch under and around those newly planted trees, shrubs, and perennials.
If you have any evergreens vulnerable to winter kill, that week of warm weather was the time to spray those evergreens with an antitranspirant. Products like Wilt Pruf or White Cloud, available in most garden centers, are sprayed on the plant and leave it protected from the wind with a thin but tough plastic cover that allows air and water through but reduces winter damage. Next time the temps are in the 40’s, give your evergreens another shot.
At least the recent snow fall didn’t hang around long enough to threaten our lawn grass with snow mold, those grey crusty spots that show up in the spring after a long standing snow finally melts. Lawns that have been over-fertilized, have a thick layer of thatch and spend much of the winter under snow, will be more prone to snow mold. It is usually not a catastrophe. After raking up the debris in the spring and mowing high, the grass will usually repair itself.