Normal flower development. Each individual flower blooms and then browns, though other bloom stalks may emerge which would allow it to bloom all season. Each bloom stalk has a limited time of bloom as is the case with most flowers (off the top of my head, Hydrangeas are one of the few plants that actually holds onto the same flower head for weeks or months at a time.)

This is also a new planting, so what you experience the first year or two may not be how this plant performs over the long term. I haven't had any astilbe bloom all season, but I haven't grown your particular variety, so that may just be the varieties I have or my slowness in deadheading the old bloom stalks.

Thank you, @NHBabs! That's the best answer I could hope for! I will continue to take care of my Astilbe and hope that some new bloom stalks will emerge. Appreciate the insight!

I have come to limit my astilbe to beds around bird baths. They seems to love all the water they get from the dumping and refilling!

Great idea! I've been watering mine everyday and they just seem to want more!

Een13, here's how to add your zone and location information so it shows up in your postings.

Go to Your Houzz in upper right of every page, click Edit Profile, and on the left side click advanced settings. Well down the advanced settings page is a blank labeled Climate Zone for Garden Forums along with a link to find your zone.

If you add info on your state or the nearest large city you will get even better information since zone only relates to average coldest winter temperatures.

Then return to the top of the page and click Done Editing.

@Marie Tulin - I guess an all-season blooming flower might be too much to ask for! When I looked up the Astilbe Amethyst on the NGA Plant Finder, it said it blooms late Spring, early Summer, mid Summer and Late Summer -- I was hoping I'd have a summer full of bloom!

Regardless, I love your idea of planting several varieties. I have far more shady areas in my yard than sunny ones, so I may just follow up on that and plant astilbe in several areas for all season interest. Thanks for the suggestion!

And thank you, @NHBabs! I just set my zone so everyone knows where I'm planting!

I love astilbe too, but loved it more when I had a smaller garden. That's because they need dividing every few years. It's not a big deal and you double your plants in a couple of hours (digging up, dividing, throwing in a bucket of compost, replanting) That is absolutely no reason to discourage you from having a garden full of astilbes! t i Dividing is a basic gardening skill (pretty simple really) but You should know it is a routine part of care of quite a few plants..

Rereading your first post, een13. Under the eaves isn't the best place for them unless you are watering as you are doing. I only recently learned that astilbe are sun tolerant if adequately watered. But there's full sun in New England and full sun i n Arizona!

If your Amethyst seem to be shrinking or are smaller next spring that would suggest to me they are not happy under the eaves.

Another plus of several varieties is the repetition of the form through out the garden but with variation in the color and texture of the leaves.

Thanks, Marie! I'm happy to put in the effort of dividing them... once I learn how, that is!

I realize the placement isn't ideal. Unfortunately, we have a long walkway under that 10' eave I mentioned where we just need some green. We've tried garden ornaments and even fake flowers (gasp!), but nothing compares to real living plants. So I'm willing to water them regularly for the joy of seeing something growing there. The leaves are thriving... if those keep up and the blooms don't, I'll still be a happy camper!

My leaves are thriving but my flowers are brown. Should I deadhead the flowers and hope for a late summer 2nd bloom?