Answer: My first guess when I hear "lush foliage but no flowers" is overfertilization with nitrogen. Do you fertilize your lawn? Lawn fertilizers tend to be very high in nitrogen, which encourages lush foliage at the expense of flowers. Even if you are not fertilizing directly, could the fertilizer have been inadvertantly spread too close to the bed?
If yours doesn't flower this year, it's obviously unhappy. You might want replanting a few in well-amended soil, in a slightly sunnier spot. Be sure to water regularly during the growing season. Hope your astilbe rebounds and provides lots of bright plumes this year!
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