Homegrown: Sweet Potato
This delicious tuber is one of the least-demanding vegetables in the patch.
All it wants is sun and space.
Delicious tubers that grow easily and reward us with a plentiful harvest year after year.
Sweet potatoes share nothing with actual potatoes, except that they are both delicious tubers. Sweet potatoes are actually in the same family as morning glory, and have the same pretty, short-lived flowers on scrambling vines that cover the ground like pumpkin. Originating in South America, and naturalised throughout the Pacific, sweet potatoes prefer a subtropical or tropical climate, where they can be grown year round. In more temperate areas like Sydney, they’re best started in spring, and will grow through the warm months to produce a big crop four to six months later.
Sweet potato is grown from cuttings. Start by planting a healthy sweet potato in the ground or in a pot. Keep it watered and it will shoot. This is the bank for the season’s crop of cuttings. While waiting for the leafy shoots to grow, prepare a patch in the sun by digging at least two bucketfuls of compost to each square metre, and adding a dose of well-balanced organic fertiliser. Sweet potato needs good drainage, so build up a wide ridge to plant the cuttings into.
Take cuttings 20cm long, remove all leaves except the two at the top, and plant them, 30-40cm apart, into the prepared mound, with only those two leaves above the soil surface. Keep the soil moist for a week or so to encourage the formation of roots. Tubers will form from these roots. Feed monthly with seaweed solution, and water deeply during dry periods.
Sweet potato is a very satisfying crop for novice gardeners as it’s not bothered by pests or diseases and bolts along without much attention, producing piles of growth. All those leaves power the photosynthesis that turns sunlight into sugar, but if the growth is getting out of hand, the vines can be trimmed and the prunings used as cuttings for friends, or feed for the compost.
As it scrambles over the ground, new roots - and potential tubers - will form wherever the leaf joints make contact with the soil. You can encourage this and increase the harvest.
To harvest the crop, use a garden fork to loosen the soil and expose the tubers. Harvest what you need and leave the rest to continue growing. You’ll need to pull up all the tubers before winter, except in the tropics, where plants can live and produce for years. Wash the harvested tubers and air dry them before storing in the fridge, or somewhere cool. Enjoy over winter, but remember - you’ll need to save one to start the cuttings again in the spring.