Does anyone know (or point me to someone who does know) what the physiological basis is for why white flowering dogwoods bloom in Florida and the red (and pink) forms do not? Where do the rubra forms of Cornus florida originate?
According to the attached document by UFL, they don't do well in most areas of FL, because of the high temperatures.
Even the white flowering forms become less common in the wild, as you leave the Piedmont area and travel into the Upper Coastal Plain and southward.
I have 2 of the pink forms, one receives morning sun and blooms reliably, the other one is in full shade and only produces a few scattered blooms each year.
I started about 48 years ago with 12 trees, all, except 4 of those have died of old age. 5 were replaced with seedlings from the original trees and three with purchases, two of those were Cornus kousa. I have several Kousas, growing in pots, to replace the original remaining trees, once their life span is exhausted.
Here is a link that might be useful: Flowering Dogwood