Perennials, herbs, phlox...and shade-loving,winter-proof annuals?
We have a couple planters by our (partly/mostly shady, well protected) front door. They're filled with pansies, and god bless 'em, they keep coming back. Problem is, now we're somewhat bored with them and want something new. Forgive me, trusty pansies! But we're also spoiled, and would like to do a mix where as much of it will survive the winter outdoors as possible.
I don't really know much about annuals (or container gardening). Any chance in heck those lovely New Guinea impatiens can winter over, if protected? If not, any other shade-loving, long-flowering annuals that just might make it through a z6-7 winter?
What about perennials for this spot, like phlox? Not exactly long-flowering, but would it work? I'd consider day lilies, but they'd fill the whole pots and not leave room for anything else. I'd definitely like a mix of things, where at least something was a long-lasting flower.
I'd mix in heuchera (corral bells) or astilbes for the foliage, but they're both relatively large and fast growing for a 24" pot. Don't think that'd leave much room for anything else. True? Are there mini varieties?
Trailing lobelia? It can take shade, right? At all winter hardy?
Vinca would probably winter over, right? In the end, I'll probably just go with that. Any varieties people like?
Lastly, what about herbs? Any shade-tolerant ones that would mix in well -- and maybe, just maybe, either winter over or self-seed themselves sufficiently to come back? One greenmarket vendor suggested purple basil. Anyone used that? Anything else?
I realize there are a few different issues in here -- and that in addition to everything else there are moisture and soil compatibility issues -- but am grateful for any input!