As I sit here at my desk, looking out at a gray, moist day with a temperature of almost 70°F, I wonder if I should have typed “Protect Your Plants in Case of Cold Weather,” because we certainly haven’t seen many days that resemble winter. At least, we don’t have to slog through slush and snow in cumbersome boots and heavy coats, especially in the dark, early mornings, but balmy weather can lead to detrimental effects on plants, especially if we have a fast, vicious cold snap.
In winter, most trees, shrubs, and perennials enter a state of dormancy, defined as cessation of active growth of leaves, flowers, and fruit. In the fall, as temperatures drop and daylight hours shorten, plants undergo a series of changes that prepare them to rest during cold weather. Active growth slows, then stops during the winter months.
Tree roots continue to grow and perform some necessary metabolic activities, as long as the soil temperature remains between 32° and 41°F., although growth will be slower than...