Many of us have probably noticed our typically spring flowering trees and shrubs suddenly blooming and leafing out again right now. Some of these plants include Bradford pears, cherry and redbud, among others. So what is going on?
It is likely a stress response related to Hurricane Florence. Late winter and spring flowering trees and shrubs begin to develop new flower buds for the following year after they finish flowering and during the summer when they are in full leaf.
There is a complex relationship between flowering response, plant hormones and plant chemistry. Day length and temperature play an important role in when plants flower, and when seasons change plants respond by altering their internal chemistry and hormone levels. This is normal, but when storms come through and change the conditions directly around the plant, it can trigger an unusual response such as plants blooming out of season. The storm can lead to stress which leads to a change in the plants’ hormone levels and chemistry. Thus, plants bloom at strange times and may even produce leaves where others were lost. Bet you didn’t think the answer would involve a lesson in plant chemistry!
The next question is how will these plants perform next spring when they should typically be flowering? It is going to be unlikely that the trees and shrubs will bloom again in the spring. They may have a few blossoms left over after this flush, but blooming will be much diminished, if at all. There should be no problem when it comes to developing new leaf buds and leafing out in the spring/early summer, but they are using some of those preformed leaf buds as well now, and so you might see some regrowth, late leaf flushing, or reduced leaves at the beginning of the season.
If the trees are otherwise healthy, there should be no long-term effect to the production of new leaves.