When to Harvest Sweet Potatoes for Maximum Size

Sweet potatoes can be harvested any time before frost kills the vines—typically 100–120 days after planting. The longer they stay in the ground, the larger the roots grow. Gently dig a few test plants to check size.

If you harvest the whole crop, cure them in a warm, dark place for a week before storage. This "suberizes" the skin, making it resistant to abrasion and rot, which dramatically extends shelf life.