|Botanical Name:||Sophora microphylla|
What does it look like?
Kowhai is famous for its beautiful yellow or golden flowers, which appear in early spring. Their nectar is a favourite food for tui and kereru (wood pigeon). The pods which appear after flowering each contain six or more seeds. Unusually for New Zealand plants, some species of Kowhai are deciduous, losing their tiny, dull green leaves each winter. Some species also pass through a juvenile stage of densely tangled foliage (branches and leaves) for six to ten years before they start to flower, eventually growing into a small tree up to ten metres tall.
Where does it grow?
Kowhai may be known as New Zealand’s national flower, but it also grows in Chile and on Gough Island in the South Atlantic. Kowhai is widespread throughout lowland New Zealand, found in open forest and along side rivers and forest edges, up to 800 metres above sea level. It grows well on a range of soils and withstands moderate exposure to wind. Frost hardy (able to withstand frost without harm) when mature, it is easily damaged by frost when young.
Seed Collection and propagation
The secret of germinating kowhai seeds is to collect them early. Once the seed pods dry the seed coat becomes impervious to water unless nicked with a sharp knife or scalpel. Soak seeds overnight and sow in a warm, sunny spot. Germination should proceed within 20 days. A plant 30-40 cm high can be attained one year after germination.
Growing tips … in your plant growing unit
Kowhai should be potted on from the root trainers into milk cartons as soon as they are about 20cm tall. They use up mineral fertiliser quickly and a couple of applications of liquid fertiliser during the spring will encourage growth. Kowhai is usually grown from seeds, which germinate better if scarified (scratched) or put in boiling water to soften the hard seed coat. Kowhai can also be grown from cuttings. Kowhai are frost tender, so plant out seedlings or cuttings in their second year when they are 30 cm or more in height.
Planting out for soil conservation
Kowhai is good for controlling stream bank erosion, so plant on stream edges where erosion control is needed. Kowhai is also good for planting at the edge of bush, because it prefers open areas, good sunlight and damp conditions.
Used to …
Maori used kowhai’s attractive, hard and durable wood for paddles and adzes. They made poultices for the bark and applied them to wounds and tumours, and infusion (tea) of the bark to treat internal pains, bruises and broken limbs and wood ash of the tree to treat ringworm. The kowhai’s flowering in early spring told Maori it was time to plant kumara.
Did you know … ?
New Zealand has three common kowhai species and different varieties of each species come from different parts of the country. To avoid “genetic pollution” – mixing genes between the different species and varieties – only seeds taken from kowhai naturally growing in an area should be planted out there. This is called “eco-sourcing”.
Download Kowhai information sheet