Cabbage Tree*

Maori Name: Ti Kouka
Common Name: Cabbage Tree
Botanical Name: Cordyline australis

 

 

 

Where does it grow? What does it look like?
The young cabbage tree has a single, grey coloured trunk and later adds more trunks and branches with leaves clustered in bunches at the tips. Growing 12-20 metres. The long narrow leaves may be up to a metre long and the trunk 1.5 metres in diameter. The bark is thick and tough, like cork and the tree has a strong tap-root. In November to January hundreds of strongly scented white flowers form in clusters, attracting bees. The flowers form bluish-white berries which birds like to eat.

Cabbage trees are common throughout farmland, open places, wetlands and scrubland of the North and South Islands, but are rare on Stewart Island. They are found up to j800 metres above sea level in anything from wet swampy ground to dry windy hill slopes. Frost tender when young, they prefer full sunlight, so they are common on farms. This species is not found in forest.

Seed Collection and propagation
From January on cabbage trees almost look like they’re flowering because some are so heavy with seed.  The trick to know is that cabbage tree seeds go white when ripe. It’s very easy to grow cabbage trees from seed but NOT so easy to collect. Cabbage trees are always taller than you’d expect so you can nail an ice cream container to the end of a long stick to knock them off but one of the best ways is to lay a sheet out around the tree and then get a long stick and gently bang the seed heads.

The seeds are very easy to grow from then on. It’s best to soak them for a couple of days to get the fleshy outer coating off them – that cuts down on fungal problems with the seed. Then rub them between your hands to de-husk them. Then you sprinkle them on a coarse seed raising mix and in two to three weeks they’ll come up.

 Growing tips … in your Plant Growing Unit or Shade House
Young cabbage trees look a lot like flax; you can tell the difference because they have narrower, sharper leaves than flax and do not have flax’s distinctive mid-rib on the under -side of the leaf. Cabbage trees can stay in their root trainers for their year in your Unit.

Planting out for soil conservation
Cabbage trees are good “colonising” species – they grow happily on bare ground or exposed places. Their strong root system helps stop soil slip on steep slopes. Because they tolerate wet soil, they are a useful species for planting on streambanks to control bank erosion.

Used to …
Maori used Ti Kouka both as a food and as a fibre. The root, stem and top are all edible, a good source of starch and sugar. The fibre is separated by long cooking or by breaking up before cooking. The leaves were woven into baskets, sandals rope rain capes and other items an were also made into tea to cure diarrhoea and dysentery. The name ‘cabbage tree’ cam from Captain Cook and his sailors, who ate the shoots to prevent scurvy. The trunk of the cabbage tree is so fire resistant that early settlers used it to make chimneys for their huts! Conveniently, too, the leaves made fine kindling.

Did you know about the Cabbage Tree mystery?
In about 1987 cabbage trees started suddenly dropping their leaves and dying from blockages that stop the movement of water and food through the transport tissue inside the trunk. After nearly five years of work, scientists found the cause is a microscopic “mycoplasma-like organism” – MLO for short – that resembles both a virus and bacteria and is spread from tree to tree by a tiny sap-sucking insect. There is still no cure, so we need to keep planting more young cabbage trees to replace the dying populations.

Download CabbageTree information sheet

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