Kumara need light/sandy soils with a hard pan about a foot under the surface (Maori carried sand long distances to improve heavy soils). If your soil is too heavy, the beautiful coloured skins will be covered in a patchy brown virus. If there is no hard pan, and you have fertile soil, the tops will go for miles and you’ll get no kumara.
Plant your tipu when the Pipiwharoroa changes his tune in Spring (when his call gets a long tail on it). Bend the roots of the tupu under, into a J shape when planting so the roots face up to the top again under the ridge of soil, facing north. Traditional additions to the soil were baked ground shell, seaweed, and wood ash.
Kumara store well in a cool dark place after having been left in the sun for a few days and then turned and left another couple of days and then wrapped in newspaper or sawdust and stored in boxes.
More detailed information on kumara growing can be found here
