When Europeans arrived in New Zealand, six introduced cultigens (cultivated plants that have no known wild ancestor) were being grown by Māori. They were:
These plants were brought from Polynesia by the ancestors of Māori when they arrived in New Zealand around 1250–1300 CE. Other food crops, such as arrowroot, banana, breadfruit, coconut and sugar cane, may also have arrived on the voyaging canoes, but could not be grown in the new country’s cooler climate. Some plants may have been introduced to New Zealand more than once, possibly coming from different island groups.
Polynesians cultivated a number of plants which their ancestors had taken eastwards across the Pacific from Asia. Taro was most commonly grown on islands with a high rainfall, like Samoa. Yams fared better in places with separate wet and dry seasons, like Tonga. Breadfruit and bananas were the main crop in the Marquesas Islands and southern Cook Islands.
Polynesians linked the calendar year and rituals to the annual growth cycles of these crops.
Evidence of early Māori gardening remains as microfossils in the soil. These include pollen, starch grains and phytoliths (minute silica deposits present in plant stems). Micro-remains help scientists identify where different plants were grown. Pollen from hue, and possibly from aute, has been found in soil. Starch grains and xylem (water-carrying tissue) cells from kūmara have been detected in a number of soils and storage pits, and taro and yam starch grains have been found in Northland.
Unlike the Polynesians’ other cultigens, kūmara is indigenous to South America and did not come across the Pacific from the west. Archaeological research on the settlement of Polynesian island groups and their horticultural history points to kūmara arriving in Polynesia between 900 and 1100 CE. The seafaring Polynesians had large, double-hulled sailing canoes, and the navigating skills and ability to travel across large areas of ocean from one island group to another. It seems likely that some travelled to South America, and returned to Polynesia with kūmara.
There were a number of domesticated crop plants in South America, so the question of why the Polynesian visitors chose kūmara to take home is intriguing. Archaeologist Helen Leach has suggested that kūmara was adopted because of the similarity of its leaf shape and tubers to the yam (already grown in Polynesia). Unlike yams, however, kūmara could be grown year-round, and could be reproduced by planting rooted cuttings instead of tubers.
Kūmara was a minor crop on most islands – it became the dominant crop only on Rapa Nui (Easter Island) and in New Zealand. Growing practices and rituals associated with yams were transferred to kūmara.
Linguistics and archaeology suggest that the Society Islands, or Mangaia in the Cook Islands, may have been the source of the kūmara varieties brought to New Zealand.
Hue (bottle gourds) were once believed to have originated in South America. But DNA research in the early 2000s suggests that the gourds grown in Polynesia and New Zealand are a hybrid of American and Asian species. Scientists think that gourds were either deliberately introduced from Asia and America, or may have floated across the sea to Polynesia and then been grown from the seeds inside.
In Polynesia, it was common to plant kūmara and yams on mounds. Gourds and taro were grown in shallow hollows to retain moisture. Polynesians built stone walls and rows for shelter and as boundaries around the gardens. They also used fences and shallow ditches.
These methods were brought to New Zealand, where the Polynesian colonists quickly learned to adapt their planting regimes and techniques to the cooler climate. The growing season was restricted to the warmer months, and they added coarse sand and gravel to soil – probably to improve drainage, increase the temperature and extend the period of plant growth. This was particularly important from Marlborough south to Banks Peninsula (the southern limit of kūmara growing).
The planting, tending and harvesting of the main crop, kūmara (sweet potato, Ipomoea batatas), was accompanied by many rituals, believed to ensure plentiful results. Traditional kūmara plants were different from modern varieties – they were bushy, with few runners, and long, thin tubers. These early varieties had white skin and white flesh, or red skin and purple flesh. Tubers were planted in puke (mounds) in spring and the crop harvested in autumn before the first frosts. Early European visitors described in detail the ordered and tidy state of the kūmara gardens.
After harvest, the kūmara were sorted to remove any damaged tubers, and placed in storage pits designed to maintain an even temperature and high humidity through winter. This helped preserve the tubers to be eaten in winter and spring, and the seed tubers to be planted for the next year’s crop.
Hue (gourd, Lagenaria siceraria) was grown primarily for its fruit, which were made into containers when mature. In summer, the small immature fruits were eaten. Gourd plants were grown in hollows, as they preferred moist soil, and the trailing plants may have been grown up stakes. In 1769, William Monkhouse, surgeon on James Cook’s ship the Endeavour, reported gourd plants being grown over houses at Anaura Bay on the East Coast. In Māori tradition, the hue originated with Pū-te-hue, a child of the god Tāne.
Aute (paper mulberry, Broussonetia papyrifera) is a shrub or small tree that is abundant throughout Polynesia but does not appear to have thrived in New Zealand. The plant was a valuable source of tapa cloth in Polynesia. Bark was stripped from the stem, beaten and felted with a wooden beater on a hard surface. Only small quantities of cloth were made in New Zealand – it was observed in the Bay of Islands in 1769, worn as small rolls in earlobes. Tapa beaters are reported from as far south as Taranaki, which may indicate the southern limit of aute cultivation.
Taro (Colocasia esculenta) was grown for its starchy tuber. It was considered a kai rangatira (food for important people). Early explorer William Colenso named 10 varieties from Northland, some of which were only eaten on particular occasions, and another nine from the East Coast and Hawke’s Bay. Like kūmara, these varieties were distinguished by size, sweetness and colour.
Taro needs plenty of moisture, and microfossil analysis of peat soils in Northland has shown that taro was grown in swamps with elaborate drainage networks to maintain appropriate conditions. These sites, which are similar to the Polynesian wetland ditch-and-irrigation systems, were no longer in use by the late 18th century. Only dry-land taro gardens were reported by early European observers, who saw taro being grown in hollows or on flattened areas.
Very little is known about uwhi (yam, Dioscorea species) cultivation in New Zealand. A growing period of eight months or more is needed for the tubers to reach maturity (compared to five months for kūmara). As a result, yams could not be grown in many areas, and yields may have been low. Eighteenth-century European visitors saw yams growing in gardens in Northland, and in Tolaga and Anaura bays on the East Coast. The plants have a twining habit and, like kūmara, were planted on puke (mounds). However, introduced vegetables – especially potatoes – later replaced yams.
There are different traditions about the arrival of cultivated plants in New Zealand. The Horouta canoe is said to have brought the kūmara, taro, hue and uwhi. Ngāti Whātua believe that Kui, a wife of the ancestor Tumutumuwhenua, introduced taro and hue. In another tradition, the Tainui waka arrived carrying hue, aute and kūmara.
Tī pore (Pacific cabbage tree, Cordyline fruticosa) was grown primarily for its tap root, which, after bruising and steaming in a hāngī (earth oven), was sweet and edible. The central shoot and stem pith could also be eaten. Tī pore is now extinct in the wild in New Zealand, but grows well on Raoul Island in the Kermadecs, where it may have been introduced during Polynesian voyages south to New Zealand. The shrub-like plant was reproduced vegetatively, but took several years to reach maturity. It seems to have been grown only in the Far North of New Zealand. Polynesian settlers assigned the name tī to the native New Zealand cabbage trees, also a Cordyline. They cooked the root in a similar way, but did not cultivate the plants.
Ballard, C., and others, eds. The sweet potato in Oceania: a reappraisal. Pittsburgh: Dept. of Anthropology, University of Pittsburgh; Sydney: University of Sydney, 2005.
Best, Elsdon. Māori agriculture: the cultivated food plants of the natives of New Zealand: with some account of native methods of agriculture, its ritual and origin myths. Wellington: Te Papa, 2005 (originally published 1925).
Horrocks, M. ‘Polynesian plant subsistence in prehistoric New Zealand: a summary of the microfossil evidence.’ New Zealand Journal of Botany 42 (2004): 321–334.
Leach, Helen. 1,000 years of gardening in New Zealand. Wellington: Reed, 1984.