I don't know about seed, but I wondered about carrying them over too, so I did a search a few weeks ago. One of the other forums had a thread that talked about taking cuttings. Apparently best luck was had by taking new growth, using a moist 50/50 vermiculite/perlite mix, rooting hormone & sealing them.

Million Bells are sterile, so they don't set seed. That's what makes them relatively expensive, but that's also what makes them bloom all summer without needing to deadhead. Cuttings are the only way to propagate this plant at home.

Unfortunately (speaking only from my own experience, here), you'll be battling aphids all winter. The one year I tried, I ended up throwing out all the cuttings in frustration.

Suggestion: Buy a couple of plants really early next season and take cuttings then. By the time you're ready to put out your annuals, you'll have the Million Bells plants you need, and you won't have had to nurse and baby them through the long winter months. :-)

I have come to the same conclusion - I tried to overwinter them one year and they were just awful with spider mites so I threw them out. The suggestion of buying them early and taking cuttings is a good one, I know some of us did that this spring. I am going to try it with New Guinea Impatiens this spring if I can find them early enough - they cost a fortune and you can't get seeds for the newer varieties.

I bought 2 pots of million bells this year and ended up with about 20 plants. They root really easily. I just used one of those long propagators with the clear dome, put the soil directly into the bottom, soaked it well then just stuck my cuttings into the soil and put the lid on. No rooting hormone, I just made sure they were kept moist, within a couple of days they were rooted. I'll definitely be doing that again next spring!