It was a beautiful year for flowering redbud trees this spring. The pink flowers seemed to go on and on. As in past years, the question arises as to why redbud trees flower on the trunk or on large branches. The question just popped into my email inbox this morning: Is it a disease? Like everyone else, I’ve always meant to look up this interesting phenomena.
According to Michael Dirr (Manual of Woody Landscape Plants) and the Virginia Native Plant Society (https://vnps.org/wildflowers-of-the-year/2013-woty-redbud/), it turns out that flowering on the trunk or limbs aka ‘cauliflory’ is a normal growth characteristic for redbud trees. Flowers are produced in pink nodal clusters that can develop on any part of the tree, from twigs to branches, as well as the main trunk (particularly on old trees).
So now we know.