About 5 or 6 (or 7?) years ago, I planted an astilbe in my very shady garden. I can't remember what variety it was. It hung on, kept sending up foliage year after year, but didn't grow much, and never flowered. I was pretty sure the spot I'd picked was just too shady, and finally last spring I moved it when it came up to a brighter spot. Well, it grew much bigger than ever before, and looked pretty happy, but it still never sent up flowers. What's the deal? Did I just get a dud, or could it still decide to flower one day? Or do my conditions just not suit?
Where I think I've seen astilbe flourishing and looking nice, it's usually constant bright shade, as opposed to intermittent bright sun and dark shade. Which is what what I have in the spots that get any sun at all. Thoughts?