Mothplant pods and flowers on a vine.
Photo: Northland Regional Council

Participants in a Northland competition have stopped more than 1 million future moth plants taking hold across the North.

Participants in the first-time competition have so far collected about 200 tonnes of highly-invasive pest’s pods and more than 13,000 triffid-like vines.

Entrants earn points for removing moth plant pods and whole vines from the environment, with prizes awarded to those who eliminate the greatest number.

“We’re hell bent on winning a prize. We really want the money to buy more natives to plant towards restoring our local ecosystem,” Waimahanga Track Action Group co-ordinator Chrissie Stephenson said.

She and her community volunteers have been madly collecting for the competition and at publication time had 761 pods and 449 vines.

The total haul from the Northland Regional Council (NRC) competition at publication had seen almost 10,000 moth plant pods collected – with about a month of the competition to go.

Northland is New Zealand’s moth plant epicentre because it is warm, frost‑free, windy and heavily coastal.

The invasive vine was established in the wild in the early 1900s, giving it endless opportunities to spread and reinvade.

The competition started on 23 February and ends on 15 May.

Whangārei Heads mega moth plant movement co-ordinator Kate Hardcastle outside the Parua Bay community house with the skip bin full of moth plant pods locals have collected for disposal as part of tackling one of New Zealand’s worst plant pests in their own back yards.
Photo: NZME

NRC’s biosecurity officer pest plants Graham Norton said the biggest single competition entry to date has seen 6368 pods and vines with roots collected.

“Going on the numbers of pods and vines collected so far, the community will be having a real impact on reducing numbers of this invasive vine,” Norton said.

Each moth plant pod can produce up to 1000 viable wind-borne seeds, enabling the vine to spread long distances and smother native vegetation.

The plant’s sticky nectar can trap and kill insects such as monarch butterflies.

Competition entries climbed by almost 40 percent in a week around Easter, with now 114 entries, up from 82 on 25 March.

Boosting the native ecosystem along Onerahi’s Waimanga Track is the mission of Waimahanga Track Action Group says leader Chrissie Stephenson.
Photo: Susan Botting / Local Democracy Reporting

Norton said these had come from across Northland with teams from families, communities and schools.

He said it was particularly pleasing to see the number of pulled vines. They were included in the competition because their removal had a larger impact on the moth plant population.

Moth plant is widespread across Northland. Whangārei Heads has the region’s biggest moth plant problem, followed by Kerikeri and the Mid‑North, with lower but emerging risks in the Far North, Whangārei urban areas and inland Kaipara.

In Whangārei city, Onerahi including where it slopes to Whangārei Harbour, Riverside, Otangarei, Morningside, Tikipunga, Te Kamo and Raumanga are the worst moth plant hot spots.

Huge community effort has been underway at Whangārei Heads for more than 20 years to get on top of the invasive weed where the biggest infestation covers the equivalent of several rugby fields.

Locals there are now also fighting the pest via the five-year Whangārei Heads mega moth plant movement project started in 2024.

Project co-ordinator Kate Hardcastle said it was good to see NRC’s new region-wide competition bring more attention to the invasive pest.

Hardcastle said a just-completed three-month community collection outside Parua Bay community hall had filled a six cubic metre skip bin – roughly the size of a family car – with moth plant pods.

The group also runs an annual stop-the-pods competition in early summer which focuses on getting rid of vines before they can form the hand-sized pods.

Next year it will repeat a new moth plant pod weigh-in competition in conjunction with Whangārei Heads School’s March funky fish event.

A former avocado picking tool comes in handy for plucking pods high up in native tree canopies.
Photo: Susan Botting / Local Democracy Reporting

Ocean Beach resident Rupert Newbold likened moth plant vines to triffids.

He said he had been dealing with the pest on his Whangārei Heads farm for 15 years, removing about 15,000 plants.

“People underestimate moth plant through lack of knowledge. But they need to take it seriously otherwise it will take over the whole of the North Island,” Newbold said.

A three-month Whangārei Heads mega moth plant movement community moth plant pod collection outside Parua Bay’s community house that finished in April filled a six cubic metre skip bin – roughly the size of a family car – as the local community did its bit to get rid of the highly invasive pest.
Photo: Supplied via LDR

Moth plant vines smother native trees, dominate forest margins and reinvade sites rapidly through long‑distance wind‑borne seed dispersal.

They infest coastal cliffs and islands through to urban reserves, roadside margins and home gardens, which elevates their threat above many more-localised weeds.

Whangārei Heads resident Geoff Pike has been fighting the ‘extremely invasive’ moth plant for 20 years.

He has taken out about 20,000 vines from his coastal farm between Taurikura and Ocean Beach and is not yet on top of the problem.

Pike said it was great to see the NRC competition, but wanted the council to springboard from there to develop a supported regional plan to attack the invasive pest plant head on.

– LDR is local body journalism co-funded by RNZ and NZ On Air.