I compost them, but I'm also practicing some pretty serious selection from the volunteers.

I probably get 2-300 volunteers per year, and I select for color, texture, blade-width etc.. The keepers are the bluest Festuca, the finest-blade Miscanthus, etc.. They get potted up, and wintered in nursery beds.

Everything else goes into compost, because all my friends and neighbors are also grassed out.

I have sold quite a few to landscapers and nurseries, though. I love the look on a nursery owner's face when I walk in with a flat of a half-dozen trade gallons of Festuca which are bluer than anything he's got in stock. I will frequently trade for something he's got which I don't.

I'm glad I don't get that many....

I thought of asking a nursery if they wanted them, perhaps I'll try that. Thanks

How about donating them to your local garden club if they have a plant sale. Or .. how about having your own small plant sale in the spring. That is how i always 'got rid' of extras & how I paid for all the new replacements :o)

I tried selling potted up divisions of perennials and grasses last year and didn't make a single sale. I certainly could use the money for more plants....

I have given away a few extras at plant swaps. Also, you can give them away on Freecycle or Craigslist. A local plant sale is a great idea! I have sold a few perennials on Craigslist, and a couple people wanted some of the popular grasses like Calamagrostis Karl Foerster, Panicum 'Shenandoah', and Miscanthus purpurascens.

I've got some seedlings in the garden, that I'm letting grow instead of weeding them out, to see what they look like. For example, my Deschampsia caespistosa (Tufted hair grass) reseeds a lot, and it's such a pretty grass that grows easily in partial shade (with a little moisture).

There are a lot of plant swaps organized on Garden Web for Washington but very few for Oregon. I went to one last year but it was pretty sad though I did get a great recipe for zucchini bread. I've had too much on my plate to organize one.
I have given away other plants through GW though. I always hope they'll keep coming back for more :)

I did talk to my friend who owns a nursery the other day and she did say she would take some black mondos in trade next spring.

When I have extra plants I post in the free Craigslist section with a phone number and always get quick response.
I have tried selling plants but its not worth the hassle.
At least maybe it encourages more gardeners and habitat by giving them away.