Also known as Kumera, a perennial trailing tuber, developing over the warmer months. Plant in spring and harvest 4 to 6 months after planting. Highly digestible, rich in vitamin C, just as useful as ordinary potatoes in the kitchen, and have a distinctive sweet flavour.
Sweet potatoes are easy to grow but they do need a few things to grow really well. They need well dug, compost rich soil, and good drainage (essential). Plant in raised beds or on mounds 15cms high. This will avoid tubers rotting in wet weather. Before inserting the cuttings, spread a handful of all purpose fertiliser (avoid high nitrogen fertilizers or you will get lots of leaves and not enough tubers). Sweet potatoes don’t need much water and are vigorous with a habit of scrambling through the garden like pumpkin.
Harvest once the leaves start to yellow. The longer you leave them in the ground the better, but must be lifted before any frosts or tubers will rot. Dig up carefully to try and avoid nicking or slicing into the tubers. Leave in the sun to dry for a few hours. Sweet potatoes can be used fresh from the ground but will be sweeter if cured. This is simply storing in a warm (30ºC) airy space for 7-10 days. You can line boxes or baskets with newspapers and leave in a greenhouse or any space where the temperature is stable. After curing, store in a cellar or basement, ideally at around 12ºC.