Sweet potatoes just like our kūmara are grown all over the world. Most of our nation's best kūmara is grown in Northland where the climate and soil type suit it perfectly.
There are three main types – red, orange and gold – and quite a few varieties of each. I had assumed, perhaps like many people, that the kūmara we eat and grow today are descended from those bought to New Zealand by the Maori over 1000 years ago. It turns out that this variety produced rather small kūmara, no bigger than finger size. When the whaling ships sailed in with larger South American tubers on board in the 1850s, growers saw a chance to improve the stock, and that's what we grow today.