Opinion: I was brought up on a rural property in South Taranaki. The scourge weed of that time and locality was gorse. As a weed species, gorse had everything going for it. It was hard to control by hand, it was hard to kill chemically and it seeded and spread with gay abandon. It had become the totally dominant weed species on many farms, especially during and after the labour shortages of World War II.
The same chemical used on gorse became the active ingredient in the ill-famed “Agent Orange”, which was used as a defoliant with devastating effect on jungles and gardens during the Vietnam War.
The herbicide 2,4,5-T was manufactured just up the road in New Plymouth and the empty drums of the concentrate were piled high at the back of our small woolshed. My father helped win a local war against gorse with 2,4,5-T but escaped without any harm done to his health.
Fast forward 60 years, and moth plant (aka kapok plant or wild choko vine) is the new weed scourge, particularly in the north of New Zealand and the coastal Bay of Plenty. Moth plant, a native of Argentina and Brazil, has been in our country since 1888, and is now spreading south.
It is winter now and there appears to be thistledown floating about. Except it’s not thistledown as the seed is too big and the time of year wrong; it’s moth plant seed, spreading absolutely everywhere.
It is germinating between the cracks in the footpaths, in the hedges, in every local bush reserve, alongside every walking track, on the islands of the Hauraki Gulf, even in my vege garden. Moth plant is unfussy – it is rampant in Auckland’s most desirable waterfront streets, and in the fences dividing the industrial units of our less loved industrial suburbs.
If this invasive, rampant weed climber is not taken a little more seriously by a few more folk, we will surrender our image of clean and green to an insidious quiet invader that will strangle our native vegetation with just as much success as it is strangling the shrubs in urban and rural gardens.
It is growing up trees in the streets with the same vigour as it is growing through the shrubs on the sides of our motorways. Sadly, not many people seem to care much.
Moth plant has a relatively small tap root that can be dug out, killing the vine above. It has a rather horrid white sticky sap, best avoided. Wear gloves while dealing to it. After flowering, it produces an olive green, almost capsicum-shaped seed pod in large numbers – as many as 1000 seeds per pod – which stay on the vine until about June, when the drying pod bursts, releasing the “down” to the wind and depositing the seeds literally and absolutely everywhere.
Auckland Council has previously done a good job of promoting the collection of these pods by school students, but sadly its website has only news of a competition among students to collect the seed pods dated June 2018. My local secondary school has moth plant growing in the trees and shrubs across its front garden. Not such a good example to the students.
Moth plant is supposedly frost tender, but not to the extent of stopping it becoming established in Whanganui and Marlborough – and it will spread south; it is too clever not to.
So, New Zealand Inc, please wake up. There is no 2,4,5-T answer to this one. It is up to us to recognise, to publicise and to destroy. Wake up before it is too late. This is the weed scourge of the 2020s. It is time war was declared on moth plant.
Roger Milne is a retired plant business and industry leader and lives in Auckland.
