low/no maintenance perennials for community garden?

[in_newengland]

You could also try sedums -- Autumn Joy blooms in the fall and needs no work at all. You can also just cut parts off, stick them in the ground and get more plants very quickly. There are lots of different sedums (I think another one is Dragons Blood) -- they don't need water other than rain and they will spread.

[PJSaturn]

In addition to daylilies, which many recommended, how about some "regular" lilies? They are so colorful and beautiful, and take absolutely no care!

[Icy Tea]

If you have any kind of a trellis or bushes, some clematis might work as a backdrop. I call the white fall blooming clematis orange blossom clematis and it spreads( which is why some people hate it) like crazy but is very robust. Morning glories reseed themselves. Snapdragons are annuals but they can be pretty much perennials of you have good rich mulch in your garden and can flower until the first had freeze. Marigolds come up from seed too if the soil has peat moss as a mulch. I had salvia come up from seed from last year and almost pulled them out for weeds until I took a closer look at them.
Zinnias are another plant I start as seed. Sunflowers also are an easy plant to grow.
You can grow quite a bit from a few dollars in seed packets if your soil is good. And don't be afraid to cruise cemetaries and help yourself to plants tossed in the trash barrels. Spring bulbs and chrysamthemums and later geraniums after Memorial Day. Rudbeckia( Black eyed susans) looks awesome in the late summer.