8 vegetables you only have to buy once. then regrow forever. Only, I wont be able to grow scallions at the rate I eat them! - Gardening For Life
Place a sweet potato in a jar of water and place it in sunlight. When the sweet potato has send out sprouts, then you can pull them off the sweet potato and plant them in a pot with soil.
Scallions: Regrow them using their discarded roots. Leave an inch of the scallion attached to the root then put them in a glass of water. Place the glass of water in a room that’s well-lit.