Sweet success growing kumera

Justin Newcombe says not only are kumara easy to grow, they also have excellent nutritional qualities. Photo / Richard Robinson

For ease of growing and nutritional value, you can't go past a kumara, writes Justin Newcombe.

Some plants just grow themselves and some, like potatoes and tomatoes are pretenders, as there is always a certain amount of anxiety involved in growing these. But for a truly easy to grow crop this summer, the kumara is surely number one.

I think it would be a great honour to have one named after you. Perhaps we could develop some especially for the Rugby World Cup, a Mealamu perhaps or how about a Kahui? To be honest Smith or Carter both sound like potatoes (I suppose that makes a change from being a heat pump) while the Williams boys in my opinion would make terrific parsnips. Spare a thought for poor old Andy Ellis who has all the hallmarks of a top drawer radish.

The traditional red kumara or Owairaka Red, with its smooth creamy flesh and dark red to purple skin, is closely related to the original New Zealand kumara which sustained Maori for centuries. I reckon it is probably the most versatile and reliable vegetable grown in New Zealand today. The kumara evolved between the Yucatan peninsula and the Orinoco River in Central America.

It is thought to have migrated from America to Polynesia via Polynesian explorers as they sailed the Pacific, eventually making it to Aotearoa.

You can bet this wasn't the only plant material they traded, but it's a great testament to its reliability, adaptability and versatility that it became the option of choice for people who couldn't afford a food crop failure.

As well as being an easy crop to grow kumara has some excellent nutritional qualities. In one study, kumara ranked at number one for fibre content, complex carbohydrates, protein, vitamins A and C, iron and calcium , way better than the second place-getter, potato.

Apart from the popular Owairaka Red, there are a lot more varieties of kumara you can grow.

There's the Beauregard Orange which, not surprisingly, originates in the U S of A. But as far as bragging rights for best name goes, you can't go past Toka Toka Gold which is named after the iconic "witches hat" shaped peak just south of Dargaville, the spiritual home of the kumara.

Although kumara are grown in the ground like a potato they're not propagated by burying the existing tuber, but by separating young vines from a tuber and planting them. Simply detach the vine once it has roots on it, plant it in a well-draining soil in full sun and water well.

To prepare the ground, plant kumara after a fruit crop such as tomatoes, eggplants, chilli or peppers, and dress the ground with lime and potash. I also place a handful of charcoal under the vine as well. This creates a hard base for the tuber to resist which seems to make them swell to a bigger size.

The charcoal also starves them of nitrogen which is good: nitrogen only encourages vigorous vine growth.

The vine will attach itself to the ground and produce lots of smaller tubers but this needs to be discouraged.

Either plant the vines through flattened cardboard boxes covering the ground or grow them up a stake.