Sweet potatoes are true roots not tubers. As the plant ages it uses the roots roots as storage. They usually begin storing when when about two months old and will continue until the plant dies. They are a perennial and will live until killed by frost. It takes about 3 months on average to form usable sweet potatoes. Many varieties never flower and for those that do has no effect on root development. They are tropical plants in the morning glory family and grow fastest at high temps and humidity.
