POSTED BY KIM — I don’t either. I was thinking about all the times I’ve cautioned people to not prune macrophyllas too late in the fall because they might cut off “flower buds,” and sure enough, you can see buds — but are they leaf buds or flower buds?
I searched a few books here, did the google thing, and came up empty-headed. So I called on the oh-so-helpful and oh-so-knowledgeable Kristin VanHoose at HydrangeasPlus.com.
She was gracious enough to do some digging and contacted Josh Kardos, Ph.D., at Plant Introductions, who said “It is not very clear cut. Usually flowers buds are larger and more rounded than vegetative buds. Not always the case though. The flower primordia are preformed, so dissecting a bud or two will allow you to determine if they are vegetative or floral. I hope this helps.”
I wonder if he was joking when he suggested dissecting the buds. As a gardener whose sole purpose is to get the maximum number of hydrangea blooms, dissecting buds sort of defeats the purpose. But maybe one day when I’m retired, I’ll give it a whirl.
But I’m glad now I know — what I don’t really know!