Sweet Potatoes don't belong to the Potato family but they are related to the Ipomoea (Morning Glory). As with the Ipomoea they are climbing plants that require a long, warm growing season and best results are obtained when grown in a greenhouse or polytunnel.
We supply them as plants and when received, they should be planted into 10cm pots and grow on in a warm greenhouse or indoors. Sweet Potatoes are not frost hardy so don't plant outside until the risk of frost has passed. When planting outside, position them 12" apart in a sheltered, sunny position, providing a cane or string support. In the greenhouse they can be planted in the border or in large pots. When using a container, fill with good quality soil-less potting compost placing one or two plants per 30cm (12") pot. The ideal temperature would be approx. 22-25°C (72-77°F).
As the plants develop feed two or three times during the growing season with a high potash liquid tomato fertiliser. Keep the compost moist as dry soils will adversely affect the development of the young tubers.
If grown outdoors the tubers should be lifted in September, before the first frosts, and those grown in the greenhouse can be left and lifted in October.
Once lifted they must be cured to set the skins and to allow the sweet flavour to develop further. To do this place them in trays and keep them in a warm room for a week. After this period they can be stored in a dry, cool, frost free place, checking them regularly for any signs of deterioration.
Although not as large as those available in supermarkets which are generally imported from warmer climes, a useful crop can be achieved in a good summer.