Sweet potato sprout

I will try potting it up but it isn't really the right time of year. I've had mixed results with sweet potatoes sprouting in spring. One year, a tuber sent up lots of sprout such that I took all I wanted and gave it away to someone else to take some cuttings off. I had a bumper crop that year. The next year, I did exactly the same and the tubers all rotted so ended up with none.
I've not been successful with cuttings from shrubs either lately. I took one in spring from a park and it has sat in a plastic bag covered pot ever since neither dying or sprouting. I suspect the leaves will start to fall off one by one soon.