For many plants, especially non-native ornamental plants, the long period of abnormal warmth has triggered the process of bud break. This process, in which leaf and flower buds emerge from dormancy, is usually triggered by the climbing sun and longer days of late spring.
These oscillations are normal, even if this year is a bit extreme, and Maryland’s native plants have evolved with mechanisms for handling them. Many native trees and shrubs have internal regulators that extend the first period of dormancy, called endo-dormancy, even when temperatures are high.
It’s not impossible for abnormal winters to affect the long term health of native plants, especially once the plants exit the second phase of dormancy called eco-dormancy.
Still, most experts are confident that the weather patterns we are currently experiencing are unlikely to permanently damage or kill native trees and shrubs. The worst outcome you are likely to experience is a decrease in flower production in 2016, though some native species may actually benefit from this weather pattern and have a better-than-average year.
What can you do?
First, if you haven’t already pruned your trees and shrubs then we encourage you to wait until cold temperatures have been around a while. Most likely, this means late January or February for plants that need winter pruning.
Second, next spring do be alert for splitting or cracking caused by the unusual winter. These problems can foster disease, so be vigilant about pruning out dead or damaged limbs.
Third, we hope you will replace any non-native plants that are injured during the winter with native plants that are better adapted to our climate and that support a broad array of native plants.