How to promote Astilbe blooms?

Question

I planted Astilbe in my shade garden late spring/early summer. I have tons of leaves and they are very tall (12″ or more) but there are no blooms. They are kept moist due to the location; I hardly have to water them. I read now that compost should have been used to promote growth of the blooms. Is there anything I can do now to get some late summer blooms? I am in coastal VA.

Answer 1

You likely have high Nitrogen in the soil, which causes lots of lush greens but little flowering.
Phosphorous can be added and Bone Meal is a good way to do this.

Here is a few links for you.

https://www.gardeningknowhow.com/ornamental/flowers/astilbe/growing-astilbe-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/bone-meal-fertilizer.htm