Discover the top tips and tricks for growing great kumara, writes Meg Liptrot.
I've never grown kumara, partly because I've never known how. I imagined it would be much the same approach as growing potato - throw a sprouted tuber in some nice rich soil and several months later you've got a sack of spuds. It turns out the procedure and requirements for kumara, known elsewhere as sweet potatoes, are a little different.
To grow kumara seedlings for planting out in spring, you need to create a kumara "seed-bed" in winter. Plant kumara tubers in sand in a raised bed or pot, keep watered and wait for the shoots to sprout. They can even be grown in a pot inside the house - the warmth will encourage shoots to grow.
Once the shoots are a good size (upwards of 30cm), detach them from the kumara and keep them temporarily in water until you're ready to plant out. Only four leaves should remain on the shoot. The shoots, which eventually grow tubers, are the stems with nodules on them. The more nodules, the better.
If you don't have time to propagate your own plants, kumara seedlings are available to purchase in bundles for a short while in spring. Before planting your seedlings, aim to build fertile sandy soil with good drainage for best results.
When planting, cover most of the stem by burying longways so the stem is more or less horizontal into the prepared raised rows or mounds. Water as often as a couple of times a day in the early stages to ensure the seedlings take. Kumara vines need plenty of space and, as they grow, gently lift the vine along its length to prevent it setting down more roots. That means the plant puts more energy into producing tubers at its base. The vines need to be handled carefully, and weeding is best done by hand.
My friend Teina is a great gardener. She said her brother planted a few kumara under his feijoa tree in his Otara garden. He built a boxed bed around the drip line of the tree into which he would gradually add vege scraps to add nutrition to the soil and ensure a great crop of fruit.
One day he decided to plant a few kumara underneath the feijoa tree. The vine from the kumara he planted in this bed grew all over their shed and the kumara dug up were huge. He made cuttings from that vine, and then planted those cuttings in cultivated garden beds. Many of the resulting kumara (as pictured) are large by anyone's standards.
This root vege was first introduced to Aotearoa by Maori. The old variety was a small bush kumara with finger-sized tubers. For Maori, planting kumara was a sacred event, involving much ceremony. Tohunga supervised the cultivation and the plants were spoken to, encouraged to grow and be healthy and were reminded of their celestial origins.
According to Murdoch Riley in his book Maori Vegetable Cooking, a kumara plantation was called The Belly of Pani, after the goddess Pani-tinaku who was given the kumara by Rongo-maui when he returned from the heavens. In the 1850s bigger cultivars were adopted, brought in from America.
Teina's flatmate Mary also has a kumara story. Mary's iwi are from the Bay of Islands. As children, their regular chore was to collect sand from the beach for the families' kumara beds to keep the soil nice and light. They would also add seaweed and cow manure.
One year, her father discovered their pet horse had died overnight in the paddock, and they buried the animal where it lay. A couple of years later he decided to turn that spot into a garden bed, and they planted kumara there. At harvesting time, they unearthed their crop, including a kumara so enormous it fed three extended families.
* In winter, grow your own sprouted shoots from quality, disease-free kumara saved from the previous season. You can even grow your kumara seed-bed in pots indoors.
* Each kumara can produce up to 12 new shoots to be cut and planted out in spring.
Kumara plants like:
* Fertile, light and sandy soil with good drainage, preferably a warm sloping site which gets all-day sun.
* Regular watering to help young seedlings get established.
* Soil rich in organic nutrients, but don't fertilise once the vine is actively growing, as it will put the energy into leaves instead of tubers.
In the kitchen:
* There are three kumara types: The red-skinned Owairaka, gold Toka Toka and the orange cultivar Beauregard. Kumara are high in dietary fibre, potassium, antioxidants and vitamin A, C and E.
* Kumara can be steamed, baked, mashed and used as a base in soups.
* Maori traditionally preserved kumara by cooking and drying. The dry tubers (kao) became a crumbly ingredient used in nutritious porridge and cakes.
Teina's tip: Large kumara aren't as sweet as the small ones when boiled, but the sweetness is retained if you bake them in their skins.