Sweet potatoes bloom every year. They bloom normally. It is rare to see sweet potato blossom, because sweet potato is a tuber plant, and we eat its roots instead of its fruits. Often before it blooms, the root is edible, and then we pull it out of the ground, and we can't see it until it blooms. In addition, sweet potato has a short flowering period and small flowers. Maybe sometimes it will bloom without knowing it. But there are also some sweet potato varieties that are cultivated and do not bloom by themselves.