Q: I have grown sweet potato’s before, but have never seen anything like this. This is the first year for our garden. The sweet potatoes that I dug were malformed and very large. These were Georgia Jet variety. One was almost completely round, with a 10”diameter, like a basketball. Any idea why they turned out this way?
A: There could be a couple of things that helped them to grow so big. If, for some reason, the original plant only initiated one potato, it would receive all of the resources of the vine. Sort of like the pumpkins that gardeners grow to be huge by picking all the flowers to leave only one fruit on the vine.
And remember that sweet potato is a perennial plant. It will grow and pump resources into the tuber for as long as the soil stays warm. If you planted early and watered regularly, the soil was plenty warm enough to promote the fast growth and big tubers you see.