I live pretty far out of sweet potato climate, very short season, cool nights, etc. This past May, in the greenhouse, I rooted cuttings from an over-wintered vine in pots that measured 4 x 4 x 6 inches deep, and when they were well-rooted - growing out the drainage holes - I transplanted 24 of them into grow bags and containers, 3 plants apiece, and another 12 out in the garden beds. I grew 'Jubilee" - a short vine, short season variety. The vines grew like bandits. I just harvested them this weekend.

Over-all weight was acceptable - I didn't weigh it all but there's at least 30 lbs. But instead of one to three large tubers per plant, I ended up with a bazillion thumb - diameter, long slender roots all twisted together under the vine, then sort of wandering out and around the containers - the only explanation is that the roots in the original rooting pots went ahead and formed tubers. It was the same thing in the containers and in the garden ground.

So I'd like suggestions on how to avoid this - should I root the vines, then trim off all the roots but one or two before putting them in their final destination?