Sweet potatoes are a subtropical crop that grows very well in Melbourne. We’ve grown them over the past two summers and have had some good results. Here’s what we’ve learnt about growing sweet potatoes.
Propagation of Sweet Potatoes
The easiest way to grow sweet potatoes is by taking cuttings from an existing vine. This can be done at any time of the year. In Melbourne, it is usually done in May when the previous crop is lifted. The cuttings can be placed in a jar of water to take root. We’ve also had success with immediately potting cuttings up in potting mix.
In Melbourne, you’ll need to protect young plants from cool weather. Cuttings will need to be protected in a greenhouse, or by growing on a windowsill during the winter.
If you don’t have access to an existing plant from which to take cuttings, you’ll need to grow some sweet potato “slips”. To do this suspend a sweet potato the tuber over a glass of water (toothpicks may assist with this). Half of the tuber should be submerged and half out of the water.
Place the glass in a warm position, such as on a window sill. After a few weeks the tuber will sprout many new shoots. Once the shoots have formed roots at their base, you remove them by twisting, trying to retain as many of the roots as possible. Place the shoots into a shallow dish of water until they establish a stronger root system and then pot up, or transplant out.
Some nurseries also sell sweet potato plants in spring and summer.
Location and Planting of Sweet Potatoes
Sweet potatoes are a subtropical plant. They need full sun to enable good yields in Melbourne gardens. Limiting their access to sunlight may limit the size of the tubers developed by the plant. Dig plenty of compost and organic matter into the soil. Plant the young plants about a metre apart. We’ve had best results by planting young plants into the garden in mid-late November. Be prepared for them to take over a space of several square metres of garden per plant.
We haven’t tried, but you can train sweet potatoes up a trellis. However, it apparently reduces the size of the tuber that develops. We have grown sweet potatoes in a “Three Sisters” companion planting garden. The sweet potatoes were a less rampant option to grow in place of pumpkin (squash in the original three-sisters). We found that once harvested, the sweetcorn plants died back and enabled the light to penetrate down to the sweet potatoes. This ensured good yields from the sweet potato vines.
Sweet potatoes need regular watering and warm weather to thrive and yield well.
Cant wait to harvest your tubers?
We enjoy growing sweet potatoes in our household. However, the yield isn’t that great considering the space the vines take up. Fortunately, you can also eat the leaves, either steamed or in salads. Sweet potato leaves are known as camote tops (or kamote tops) in Spanish-speaking countries.
The leaves are most tender in late summer. Late summer is a time that can be challenging to grow other leafy greens, such as lettuce and spinach. The heat and long days often make young lettuces bolt. So sweet potato leaves can add variety to your summer salads.
Harvesting your Sweet Potatoes
The tender vines will not cope with Melbourne’s cool weather over winter. In our climate you will need to harvest the tubers in May (or earlier if it is a particular cool autumn).
It’s a good idea to take cuttings for planting next summer prior to lifting the tubers. The cuttings will need to be keep in a greenhouse or indoors to protect from cooler weather.
The tubers are located at the base of the main stem. They are very delicate, so carefully excavate around the tuber and lift them. Allow them to dry off outside in the sun on a warm, sunny afternoon. Once dry, place them in an open cardboard box placed in a warm spot for a few weeks to cure. This helps to convert the starches to sugars and makes them a bit tastier to eat. It also allows the skin to harden off, so that the tubers will store better. Make sure rodents can’t get to the tubers whilst curing and when in storage.
Have you grown sweet potatoes before? Have you got any hints and tips on growing them?