This is Astilbe. I've written about it before but I want to emphasize that it's a great way to add some interesting texture to your garden. And talk about low maintenance. It asks for no special treatment. I inherited it from a fellow gardener two years ago when it was just a little stub of a thing. I planted it in a pot that's about 19" in diameter and now it's huge. I'm sure I'll have to divide it next spring. Astilbe comes in lots of different colors--you'll find it in white, red, and various shades of pink and purple. It is hardy to zone 4 and likes part sun. It can tolerate full sun (mine does) as long as it's not the scorching afternoon sun. And finally (drumroll please), it's virtually PEST FREE! Actually, it's completely pest free in my container garden but I don't want to make that guarantee for everyone.
Bookshelf: Container Gardening Books