My flowers are multiplying like crazy. When you thin your flower beds, what do you do with the extras?
You could post them on craigslist for sale, or give them to friends. I belong to a site called plant exchange, I think there's different areas, kind of like freecycle. You could trade your rhizomes for other plants on that.
Trade them. An ad on Craigslist should find you some swaps. I've taken plants to a local poultry swap and traded them for all sorts of things. Lots of people will swap irises to get new colors.
Also, it they aren't huge plants you can pot them and when they bloom, take them to the senior center or to a rest home and donate.