Q: Snow and freezing temperatures have me wondering how will my plants survive? If we have a nice day, what can I do?
A: You are correct to be worried about your plants since this weather can be disastrous for them. As our water heater pipes burst and our furnaces are strained beyond their capacity, our plants are stressed in many similar ways.
The hardiness and survival of plants is influenced both by their genetic makeup and by local conditions. Many of our local favorite plants are genetically capable of tolerating zero degrees and below. However, some favorites, many azaleas, nandinas, Japanese hollies and their cultivars and others can tolerate temperatures below freezing for a day or so at a time, but they sustain damage when there are freezing temperatures for several days.
And many plants will be killed when temperatures go below freezing for several days. Frozen soil ties up water and cold winds can cause "winter burn," a condition in which exposed leaves and branches dry up and die. We do have a layer of snow which can actually prevent winter burn and will act as a blanket to help insulate plant roots.
Many new special cultivars that have been popular in recent years have not been tested in this unusual weather. On that nice day that you are yearning for you should inspect your plants for damage. The most significant sign is deep and long cracks in the bark of trees and shrubs. These deep frost cracks can cause death. Brown leaves may all fall off in spring but the plant may recover.
Our best hope is that the plants were totally dormant when this freeze began so that they were as prepared as plants can be for severe conditions. There is not much you can do for your plants until they start to show growth in spring.
Contact Pat Lea at firstname.lastname@example.org.