Let it grow, then snap it off and put it in some water. When it roots some, put it in a pot and you will have some green in your house during the fall and winter. Then you could snap off some runners next spring and plant it out then.

Jay

Yeah, container grow it. You can just cut the end off that's already growing and toss it in a pot with some potting mix.

You can also keep vines growing in a gallon jug full of water by a sunny window for longer than you would think.

SP is pretty forgiving and easy to grow, they just don't like the cold.

yep i would leave it whole and let it grow until tuber gets to shriveled maybe then cut off those sections with sprouts and pot them, if you put them in say 2 gallon pots in a warm place(they don't need sun but good light). they will produce in the pots.

len

Here is a link that might be useful: lens growing sweet 'taters and pineapples

I planted a piece of SP like that in the garden. It is growing like a weed. Just one flower so far. How do I know when to dig them up?

when colder weather comes through the vines will start to die back. That's the ideal time to dig them up. Curing them a couple weeks will improve flavor.