Sweet potato
Ipomoea batatas
A tender, tuberous-rooted morning-glory relative native to tropical America and cultivated for its starchy edible storage roots for over 2,000 years. Trailing stems mound only about 9 inches tall but sprawl 8 to 10 feet wide, rooting at the nodes, with heart-shaped to palmately-lobed leaves. The species occasionally bears pale-pink-to-violet trumpet flowers, though most cultivars rarely bloom. Winter hardy only to USDA Zones 9-11, it is grown as a warm-season annual everywhere colder.
Climate fit: narrow (30/100)