As I write this, the sky is a brilliant blue, the sun is shining, and the thermometer in my garden reads a pleasant 55 degrees. However, only two weeks ago my plants were subjected to a frigid minus 17, and tomorrow’s high is supposed to barely pass freezing. It’s only February, with plenty of winter yet to come. Sometimes I wonder, how do my shrubs and perennials manage to survive such extremes?

In most years, the parts of the country that experience arctic temperatures also have a significant amount of snow. While we think of snow as very cold, it actually acts as an insulating blanket in our gardens, keeping the soil temperature relatively stable—often not much lower than 32. Then, during warm spells, such as we’re experiencing this week, that snow keeps the ground frozen. Plants stay dormant, and the roots stay buried.

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