Over the course of a few months this Buzzmaker has noted a disturbing botanical trend across the Bay.
Too many of our beloved cabbage trees – Tī kōuka – are hanging their heads (three relatively young trees in my street alone) in a rather sickly fashion, seemingly just weeks away from taking their last breath.
The fear that the once rural tree (now fashionably urban) could go the way of the dodo led us to contact Dr Ross Beever, Landcare Research’s celebrated scientist best known for his work leading the team that discovered the cause of Sudden Decline – the disease responsible for decimating large numbers of the cabbage tree.
“The culprit is a phytoplasma [specialised bacterium] called ‘Phytoplasma australiense’ carried by planthoppers [insects] which themselves get infected by feeding on infected plants; in most cases on karamu rather than cabbage trees,” Dr Beever said.
“The infected insects then fly to other plants – in the case of cabbage trees they collapse very rapidly. The incidence of Sudden Death is thus related to the number of infected planthoppers, which itself is linked to the number of infected karamu.
“The longer the tree has been around the higher the probability of it being infected – and thus we have lost/are losing many of the grand old trees.” He said it’s probable there is only one planthopper responsible – a native species called Oliarus oppositus.
Okay, Latin lesson over, but the take home message is there’s still no cure – let’s get planting. Both Greendoor Plant Centre on Havelock Road, and native tree specialists Titoki Nursery on Riverbend Road, Meanee, have good specimens of the endemic beauty available now.
I hope one day they’ll plant me in
The kind of hole they dig for horses
Under a hilltop cabbage tree
Not too far from the river that goes
Southwards to the always talking sea.
(James K. Baxter – “At Kuri Bush”, 1966)
Mark
Where have you guys been all my life! This is my project which is just getting up and running. Have a look at my nursery at the Poukawa Research Station with 1000 cabbbage trees for eventual distribution. (Still, I dobt if you'll be speaking to me after reading my letter 9if published) in the week's CHB Mail.)
PROJECT TI KOUKA
A PROJECT TO REVIVE THE ICONIC CABBAGE TREE OVER THE NEW ZEALAND LANDSCAPE
Project Ti Kouka is a project to revive the New Zealand Cabbage Tree – Ti Kouka – over our rural landscape. It is made possible through the financial support of Computershare, an Australian company that distributes company annual reports electronically, and which sponsors environmental projects through a programme known as eTree. In Australia this method of distribution is growing rapidly, resulting in cost savings and reducing the demand for paper. With every email registered with eTree’s website the relevant company donates $2 to a designated reforestation project.
Project Ti Kouka is facilitated by Ewan McGregor of Hawkes Bay. Its Patron is Fiona Lady Elworthy of Timaru. eTree is administered by Rob Youl of Landcare Victoria.
Why Promote Cabbage Trees?
The cabbage tree is an iconic and unique symbol of the New Zealand landscape, and there is no doubt that New Zealand has an emotional affinity to this unusual plant.
The most common of the five species of cabbage trees is Cordyline australus. It is found in every region of New Zealand and thrives on an extremely wide range of soils from heavy moist valley bottoms to hard steep hillsides. It is this species that is the basis of this project.
Being fire resistant cabbage trees survived the pioneer bush burns but the subsequent grazing regime has prevented new trees from becoming established. The result is that nearly all the cabbage trees over farmland are at least a hundred years old, and are showing the effects of age, disease and stock pressure. Project Te Kouka aims to revive this symbolic landscape feature to our rural vistas. This can be done through planting new trees or protecting from stock the coppices of existing trees that are failing.
The adornment and the identity of our rural landscape is the primary objective of the project. However, additional benefits of cabbage trees are their ecological contribution in that they make available habitat and food for some native birds, and the provision of shade and shelter for livestock, and in this respect they do not out-grow themselves like exotics planted for this purpose.
Process
Project Ti Kouka will promote the establishment of cabbage trees generally, but its focus will be to establish new trees over our open pasture land where they characterize our unique landscape.
There will be three aspects to this promotion:
1. General promotion and encouragement through publicity, illustration and advice.
2. Funding support where appropriate and subject to availability.
3. Trial work on cost-effective protection systems from livestock, and propagation from “poles” (similar to poplar and willow establishment) A nursery at Poukawa Research Station has been established to facilitate this.
Project Ti Kouka is not about simply subsidizing cabbage tree plantings. But while it will assist those who wish to carry out a sustained programme of re-establishment and to give plantings the care warranted to ensure success, it is also as much about motivation, and lifting the profile of the unique and picturesque New Zealand plant.
For Further information contact:
Ewan McGregor
Box 1252 Hastings.
Phone 06 873 4288, Cell 027 2237063, Email ewan-mac@xtra.co.nz