If your ferns and hostas are doing well, the astilbe should be fine as well in that same soil. Just keep it away from the drip edge of the roof so its not knocked down in a storm.

tj

Thanks tj!!! It said they reach a height of about 18". Are they prone to be floppy? Yeah, a heavy rain would knock something down if it's on the drip edge (happened before to a taller plant).
I just don't know much about them, except they seem suited for this shady garden area.
A quick search and I saw a lot of "astilbe doing bad" and related posts. So I thought I'd ask for advice.
Do you know if they can tolerate a little sun?
Thanks again! Any experience or advice on this plant much appreciated.

I have a number of astilbe planted in essentially full sun, and they're doing just fine -- but it's the lowest part of my yard, and the soil is quickly saturated during a heavy rain. My last garden was dappled-to-full shade, and they did well there too. In my experience, it's consistent moisture that makes or breaks an astilbe planting, not the amount of sun they get.

'course, the difference in sun intensity between zone 3b and 6b can be pretty dramatic. Do you have a local nursery you trust for opinions, or a public garden where you can see plants "in action"?

Deeje, not that I'm aware of. There is a "respected" nursery in this area...but two years ago I went there and spent the most money I ever have on a plant. It was a hydrangea, which I told her where I was putting it - same area, at base of house.....only to find out later it liked acidic soil. It did awful- would never bloom the right color, of course I found out. She could tell I was a newbie...I trust a local nursery when they are helpful, honest...so no. Anyway......
Yes, sun here is intense. We have hot, humid summers. It would receive some afternoon sun, the amount depending on time of year.
So, I'll take your advice about the consistent moisture.
Thanks!