Sweet potato is known as kūmara in our Māori language. We have two most common cultivars: 'Owairaka Red' (red) and 'Toka Toka Gold' (gold).
Kūmara was brought over one thousand years ago from the Pacific islands by our ancestors. This bush had much smaller tubers and was widely grown, especially in the semi-tropical regions of the North Island. At a time of pre-colonisation, we were living in peace as expert agriculturalists, and kūmara was our primary crop.
Our timekeeping, planting, harvest, and maintenance work were guided by Maramataka (the cycles of the lunar nights), bringing variety and invention to an already interesting outdoor occupation. And we practice this still today. We take the time to get up close to our plants. This gives us the ability to harvest kūmara in June and peruperu all year around.
Our ancestors closely observed four stars in connection with kūmara cultivation. Those stars are Matariki (the Pleiades), Tautoru (three bright stars in the Belt of Orion), Puanga (Rigel), and Whakaahu.
When the signs at the rising of these stars foretell a propitious season, the seed tubers were planted in September. But if these stars betokened a backward season, then the planting was postponed for a month. Atutahi (Canopus), also said to be a famous star, never enters the Mangoroa (Milky Way) but remains isolated. In the month when the kūmara is planted, that star appears towards the south, and its movements mark the time for planting.
Sprouting Your Own Seedlings
To grow the seedlings for planting out in spring, you need to create a kūmara "seed-bed" in takurua (winter). You should start by either buying your own kūmara plants from your local garden center or sprouting kūmara shoots yourself.
First, aim to build fertile, damp, sandy soil with good drainage for best results. You can also use a box or a pot inside the house as the warmth will encourage shoots to grow.
Plant kūmara tubers in sand in the raised bed, box, or pot, keep watered, and wait for the shoots to sprout.
After a couple of weeks, you'll notice shoots growing off the kūmara.
When the sprouts are 5-10cm long, you can pull them away from the original kūmara.
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, kūmara seedlings are available to purchase in bundles for a short while in spring.
Plant your kūmara in a layer of rich, organic soil mixed with compost in the ground or in pots or planters 25-25cm deep.
Keep in mind that kūmara does not like soil that weighs too much, because this can damage the plant. Keep them regularly hydrate because kūmara needs water.
As the plants grow, it’s important to make sure the foliage/leaves are kept off the soil, or rot can occur. Regularly check the leaves and keep them off the soil. They are ready to harvest in early Autumn after around 5-6 months of solid growth.
When your kūmara is ready, dig them up and dry them out for a few days. They will store well in a dry and cool place but will need to be eaten. Eating Kūmara is rich in complex carbohydrates, dietary fiber, and beta-carotene (a provitamin A carotenoid)–with moderate contents of other micronutrients, including vitamin B5, vitamin B6, and manganese.
Kūmara was traditionally cooked in a hangi (earth oven), but it’s a very versatile vegetable. You can enjoy it mashed, barbecued, and baked or use it in soups, stews, stir fries, pies, quiches, and braises. It can also be enjoyed as chips or wedges or as inclusions in salads. Kūmara goes well with all meats and also complements fruits like banana, pineapple, apricot and apple. You can also eat the leaves.