I have 2 astilbes, store-bought. They do OK in my alkaline soil. However, they don't like intense summer heat or drought. I'd recommend planting in shade and amending the area well with compost to conserve moisture.
I've never tried growing them from seeds but I do know some who have wintersown them successfully. An online friend from another forum who lives in Nova Scotia has wintersown some beautiful astilbes.
Karen
