Sweet Potatoes


Sweet potatoes are not a run-of-the- mill veggie where you just buy a packet of seeds, sow them and watch them grow. No, for sweet potatoes you need to know someone who grows their own and can provide you with runners. The bottom line is this: it takes a little effort to get your own sweet potatoes growing, but if the thought of a dollop of butter melting over a baked sweet potato makes your mouth water, then it is worth the effort!

What’s to like?

Sweet potatoes are a low-GI food endorsed by health food gurus like Patrick Holford, because they take time to digest and so keep blood sugar constant. They are also high in vitamins B6 and C, and contain vitamin D as well as minerals like iron and magnesium. In other words, they can help prevent heart attacks, boost the immune system, protect the body against toxins, and improve the metabolism. And they are delicious.

Sourcing Sweet Potatoes

Plants are propagated from rooted shoots or unrooted cuttings of vine runners. For home gardeners there are not many commercial sources of cuttings. One is Living Seeds (www.livingseeds.co.za), and orders for cuttings need to be placed in advance for planting from September to November. The second option is to beg or barter runners from gardeners who are already growing sweet potatoes. If these two sources fail, buy some sweet potatoes from a local farmer’s market and plant them in July or August. Wait for the
shoots to appear and let them run. Within 7-8 weeks the runners will be developed enough to cut into 30 cm lengths and planted.

Growing on

Mound up the soil around the stems once the cuttings or young plants start to grow. The reason for this is to prevent cracks in the soil, which are used by the sweet potato weevil
to attack the roots. Water regularly, especially 50-60 days after planting when the tubers are forming. The beauty of sweet potatoes is that once established they grow easily and vigorously without too much care, and they are generally not bothered by pests. Their only real requirement is space to spread.


Sweet potatoes should be ready for harvesting 3-5 months after planting, in time for winter. In areas that don’t receive winter rainfall, sweet potatoes can be left in the ground and forked out as needed. Don’t forget to store some good specimens for producing your own runners the following season.

Did you know?

Sweet potatoes are thought to be native to Central or South America and were domesticated some 5000 years ago, with the oldest known remnants being in Peru and estimated to be
cultivated around 8000 BC. China now grows the most sweet potatoes, although half the crop is used as livestock feed.
Try this delectable sweet potato soufflé recipe.

Tip: Letting the ground dry out before harvesting is said to improve the flavour

The Gardener