Sweet potato 'Porto Rico' (Sweet potato)

Sweet potatoes are grown from small chunks of rooted tuber which can be purchased or you can root some by cutting a sweet potato in half and laying in a bed of damp soil. Cover with soil and keep warm and moist until the tuber roots and grows leaves. In about 6 weeks these will reach 4 to 8 inches (10 to 20 cm) tall and can be planted out. Purchased tubers have the advantage of being guaranteed disease free. If your growing season is too short to start from slips take 6 inch (15 cm) cuttings of existing vines and root in water. Then plant in soil and keep in a sunny spot until weather permits planting outdoors. Plant slips out as soon as soil has warmed and there is no more danger of frost. Raised rows will keep the soil warmer allowing an earlier start. In cool climates covering soil with black plastic will also heat up the soil earlier. Space plants 12 to 18 inches (30 to 45 cm) in 3 to 4 foot (0.9 to 1.2 m) rows. Harvest before the first frost, just after foliage begins to turn yellow and die back.