Royal poinciana trees typically flower in the summer between May and July, but residents may have noticed that many royal oinciana trees around the City Beautiful are currently having an unusual fall bloom.
What is causing this extemporal blooming of some of our Royal Poincianas and other flowering trees?
There are some explanations for the abnormal behavior of trees, and one of the leading reasons is stress. Yes, trees suffer from stress conditions that create defensive mechanisms by altering the normal hormonal balance and triggering a cascade of different compounds that send emergency signals to the tree. In short, Hurricane Irma induced a tremendous amount of stress on the trees which is triggering out-of-season blooming as an evolutionary survival response. A key point in understanding how trees respond to stress is to recognize that trees and other plants have limited resources to support their physiological processes. Abiotic factors, such as nutrient availability, soil moisture, temperature, climate unexpected events, and pollution interact with biotic factors, such as insects and disease, to form stress complexes that impact tree health.
The transition to flowering is a crucial step in a plant’s life. Optimal timing of flowering depends on internal and external factors. Plants need to have accumulated enough biomass to support flower, fruit and seed formation, and the environmental conditions should be optimal for reproduction and growth. The timing of flowering is also often the result of coevolution of the trees with pollinators and seed predators, and the peak of flowering typically occurs during periods of high pollinators.
The combination of these factors, coevolution, defoliation, and lack of hydration, triggers hormonal cascades that send emergency signals, triggering out of season blooming as response to catastrophic events that makes survival a priority, and one of those, is a beautiful display of flowers and seed production because the tree panics and all resources are directed to the survival of the fittest.
