I started my attempt to get slips from supermarket sweet potatoes in March. It took ages and ages for them to start sprouting. Now I have about 4" tall plants. What can I do with them? Plant them out or try overwintering them for next year? ???
Tora, my T&M instructions assure me that the plant will not survive through our winter temperatures - maybe you could keep it in the greenhouse / conservatory ? - if you are very south you may have success, but mine went in at the end of May.
they have a very long growing season, so while they may grow even now, they wont have enouh time to produce tubers.
as for overwintering, you might be able to grow vines from fresh cuttings, rather than slips/tuber. so, if you plant it to let it grow, you can try taking cuttings in september and propagating from those, ready for next spring...???
jesse knows more, probably