Auckland the weediest city in the world

From Afternoons with Jesse Mulligan, 1:25 pm on 4 August 2017

Auckland has many titles it can be proud of, but this one is nothing to gloat about.

The city has earned the title of weediest city in the world thanks to the number of introduced plants becoming invasive. There are groups popping up all around the city to combat the spread of the weeds which are killing off native flora.

Dr Nick Waipara is Auckland council's principal advisor of biosecurity and says the Kiwi love of gardening has had some very bad consequences.

“Many ornamentals and exotics were introduced to New Zealand as pretty flowers and they’ve jumped the garden fence and gone, ‘Hey! I love this place’”.

Auckland has over 300 declared pest plants including old man’s beard, wild ginger the moth plant and climbing asparagus.

"Climbing asparagus is our number 1 worst weed because it’s getting dispersed out into our forests. It can germinate and become invasive in pristine areas.”  

Like many other invasive species it smothers out native plants.

“Like wandering willie (tradescantia) they just form thickets. They’re like the triffids of the future and they’re triffids we’re fighting right through New Zealand.”

Dr Waipara says community groups are doing their best to tackle the problem – the moth plant even has its own group - Society Totally Against Moth Plants (STAMP)

“With moth plants some people liken it to choko, but when those pods break open they produce all these thousands of seeds that have a wind born helper.”

His advice? Nip them in the bud early before they form pods.

Weeds cost the economy dear, imposing huge costs on forestry and agriculture, he says.

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