They're definitely hardy in zone 9. My soil is a clay loam which has had regular additions of compost and grit. Occasionally I add gypsum or dolomite, or lime powder as my soil is naturally acidic. For me, Anemones do best in full sun with the 'bulbs' producing many flowering stalks over a long flowering season if the weather is mild, not baking hot. Mid August to late October at least (Southern Hemisphere). I have some planted in part shade and they have produced flowers, though on leggy stalks which might be better for picking. Occasionally seed sprouts for me (usually in a pot containing something I treasure!) and grows on to flower. I leave the bulbs in the ground all year. As they get older they develop a shape that looks nothing like the tidy little bulblets you've just bought. Sometimes they separate. The bits still flower the following year. I find the singles do better for me than the double forms. They seem to last longer and don't look quite as draggled after rain. One thing I have found useful is to keep them free of monstering leaves from other plants or weeds. They do better for me with plenty of air circulation as well as lots of sun. I also give my older plants a side dressing of slow-release granules while they are in full leaf so they can go to dormancy well-fed. In zone 6 I suspect you will need to be careful about winter drainage and frost protection; or plant into big pots and use them as spring accents; or be prepared to treat them as annuals if your soil is inclined to be spring-soggy. I love the red and white ones, but next year I plan to get some of the all-white 'The Bride' for a scheme I have in mind.

linnea56, Just an update. My sweet potato vine on a big pot made it. I even barely watered it. I placed them in the basement near window to get some light. It got some light maybe 1-2 hours a day and depending on the month. The maroon version though looks like didn't make it or maybe the pot where it was wasn't deep enough. The chartreuse kept producing leaves but were pale and losing leaves too. It's outside now. But I might have to bring it in tonight since we'll get down to 38F in the next few. I'm so happy since it's somewhat a success and that I didn't put a lot of effort. Bad news, my purple fountain grass didn't make it. It stopped producing leaves around January. I brought it outside. We'll see.

I overwintered sweet potatoes in containers outdoors in FL, but that was zone 9, very rare frosts. They would die back some, but never completely and perk up again as soon as it warmed up a bit. Since you are in zone 7, I would think you could keep them alive in a greenhouse, even if the vines die back. You are only trying to stretch a couple of climate zones. I'd avoid overwatering if it's chilly in there. In Japan, maybe zone 7ish, I've seen people just leave a tuber on a sunny windowsill in the house during winter - no soil, just the root on a plate with vines growing willy nilly. I suppose they watered it occasionally. Sweet potato slips can also be kept alive almost indefinitely in just a container of water. I've done it for months on end in a gallon jug. If it were me, I'd try multiple methods to see what worked best. I'd try to get a few decent sized tubers and store them in a cool dry place. I'd leave a few in containers in the green house, and I'd take some cuttings to grow in a gallon jug in a sunny spot in the house. Sweet potatoes need sun to size up the tubers, but otherwise fairly shade tolerant. The vines will probably not die from lack of sun - cold is the primary enemy. If everything fails, I'll send you slips in springtime. I am still planting new slips for my fall crop. One's going in now probably won't fully size up, but since the vines are EVERYWHERE and need to be cut back, I might as well propagate.

Well, I don't know why you couldn't -- as a kid, I used to grow sweet potatoes in jars of water, both at school and at home -- I think everyone used to do this -- toothpicks, an old mayonaise jar, and a sweet potato. I remember I had one that grew for several years, and the vines got to be probably 15 or 20 feet long, wrapped around the window frame on fishing line. We just used to change the water about once a month, and put a little pinch of Miracle Grow in the jar every once in a while. You can also root just the slips or shoots, minus the sweet potato root, in jars or water as well. I'm sure you could grow them quite easily indoors in a pot, provided they have lots of light, either natural or artificial. From experience, I will warn you that both spider mites and whiteflies like sweet potato foliage, so be aware. Another easy way to do it, though, is to just save part of your crop to replant next year. I actually saved some smallish sweet potatos for almost TWO full years in my basement, from October 2005 until late May of this year -- they lasted beautifully, and were all "sprouty" when I planted them this year. I got a fantastic crop of large sweet potatos, but speared or broke quite a few while digging.