Kūmara need a frost-free growing season, so it’s best to plant them after the last frost date in your area. (around September to November) They usually take four to six months to mature. Kūmara is high in fibre providing essential nutrients including calcium and iron, it is a superfood of the garden and divine when roasted and used in a salad.
While kūmara shoots are readily available from your garden centres, if you’d like to propagate a cutting, (I remember this from school) simply cut a mature kūmara in half and place cut side down in a saucer of water. Within a couple of weeks, you will notice green shoots appearing. Once these are 10-15cm long, you can remove them from the kūmara and place in water to root. Place most of the cutting into the ground, bending the bottom where the roots are into a J shape – this encourages the roots to travel horizontally along the soil and not bury themselves too deep.
Preparation
You do need to prepare your kūmara bed well in advance. First, you need to find a nice sunny spot and the space needs to be generous. Make sure the soil has had compost or sheep manure, or pellets added to it. Mould up your soil into good-sized beds, and then scoop out a furrow in each bed to plant your kūmara shoots into. Some seaweed in the furrows would be an added benefit. I had always learnt to plant my kūmara seedings on an angle, but the Trust plants theirs in a J, with the roots being horizontal, and the vertical part being the green leafy end. Then cover the roots with soil and water. Some growers insist the planting direction should be facing north, and others that it should be east/west, I will leave this to your discretion.
They like to be planted in well-draining, slightly acidic to neutral soil, which has been enriched with compost to ensure good fertility. You need to space the shoots about 30-45 cm (12-18 inches) apart in rows, allowing plenty of room for the vines to spread out. They will benefit from regular feeding.
After you have planted your kūmara shoots, you need to water consistently but avoid over-watering them, and mulch to retain moisture and control weeds. You need to lift the foliage regularly as the vines grow. This is because the stems naturally put down new roots where they touch the soil. If you lift the foliage this means the plant will put more energy in tuber growth rather than leaf growth. And it is the big fat tubers that we are wanting.
Harvesting
Harvest your crop once the leaves start to yellow. Cut back the foliage and then lift the kūmara carefully using a fork. Leave them on the bed to cure in the sun for a couple of days. Cover them at night (with an old clean sack or use newspaper). Then store in a cool dry place.
