I have moved mature Astilbes mid-season with no great ill effect. Fear not! dig 'em, relocate 'em, and dont' give it a second thought.

If you put them into amended soil in a decent site, they thrive. Astilbe and Hosta are SURVIVORS.

(I love both of them!)

Actually spring is a good time to divide or transplant
hostas, especially when they're just emerging. Same with
astilbe; spring is a good time for dividing/transplanting.
So go ahead and move them around--they're both very tough.
I actually divided/moved both astilbe and hosta in the
middle of the summer last year but they both took it well
and came back this spring with more vigor!

Thanks, it seemed like moving them now was better, but everywhere I looked said move them in fall, but by fall they would all have been destroyed, or dead from lack of light.

--Mia

Haven't grown Astilbe, but I can certainly assure that as long as you take normal care of a transplanted plant the Hostas will be just fine. Just make sure they stay hydrated until you can tell they've settled in and are putting out new growth in the new spot.

If your astilbes are well established, dividing at the moment of moving will be beneficial for the plant.
Take a sharp knife and cut right in a middle of the hard woody center. Replant slightly deeper than it was originally and water. This time of the year should be no ill effect.

The astilbes are basically dying where they are, few leaves last year,a dn even less this year, and they haven't been in the ground more than two years, so I expect I won't have much to divide.

I'm gonna take pics before I move them then again later in the summer so I can be sure they got better rather than worse.

--Mia