Archaeological evidence for prehistoric gardening practices in Polynesia includes stone boundary walls, storage pits and structures, drainage systems and evidence for the modification of soil, but often the remains of horticultural practise are ephemeral. Maori developed a range of novel modifications to their traditional horticultural methods which enabled the successful introduction of the range of Polynesian cultigens into the temperate New Zealand environment, the furthest southwards these crops were introduced. They modified the soil by adding charcoal, shell and alluvial gravels to change the friability and temperature retention, and stored tubers in semi-subterannean pits for the next growing season (Jones 1991: 14–8; Challis 1976). Here, we report what we believe is the first direct archaeological evidence for the actual layout of prehistoric kumara gardens in New Zealand. Our interpretation receives support from the accounts of early Europeans in New Zealand, including Joseph Banks and William Colenso.