'Do what you can': Onerahi moth plant warrior says every little effort helps keep tree-killing vine at bay

Onerahi weed buster Chrissie Stephenson - seen here removing a moth plant vine - is urging fellow Northlanders to do what they can to combat one of the region's worst weeds. Photo / Supplied

A Whangārei woman on a mission to weed out a ruthless invader strangling native species is urging Northlanders to do any little bit they can to fight the spread of moth plant.

Chrissie Stephenson leads a group of volunteers in Onerahi trying to rid their suburb of the fast-growing invasive pest plant.

Moth plant is so widespread it's tempting to shrug and give up — but Stephenson said everyone could make a difference by keeping an eye out for it, and pulling the vine out or cutting it off at the base before the flowers had a chance to turn into seed pods.

''We have to do something, that's my motto. I can't just do nothing, so I focus on what I can do. Just by cutting the vine off at the ground, you can stop thousands of seeds going into our environment.''

Moth plant's distinctive flowers start out white then develop a tinge of purple. Photo / Tania Whyte

Stephenson said moth plant was not the only invasive plant in Northland by a long way but it was particularly damaging because it spread its seeds far and wide.

The flowers developed into pale green pods which looked like chokos but burst when mature to release thousands of tiny seeds.

The seeds were attached to silky threads which could carry them huge distances on the wind, including to island nature sanctuaries such as the Poor Knights.

Stephenson said moth plant, sometimes also called kapok vine, climbed up tree trunks and developed a huge mass of leaves, eventually smothering and killing the host tree.

She had recently saved two mature pōhutukawa in Onerahi from death by moth plant.

Moth plant pods are poisonous but sometimes mistaken for chokos. Photo / Supplied

The problem seemed especially bad this year, which she put down to a warm start to spring giving many weeds a head start.

Moth plant could be especially troublesome in horticultural areas such as Kerikeri because the vines climbed to the top of tall shelter belts. The higher the pods, the further the seeds could travel.

That was why her group focused on ridges and high areas around Onerahi.

She urged people not to feel overwhelmed but to do what they could in their own neighbourhood. They could also seek advice or help from the Northland Regional Council or their local Landcare group.

Her crew, the Onerahi Weeds Group, was made up entirely of volunteers.

"Some can't help with the physical work so instead they go around and Sherlock, telling me where there are infestations," she said.

"We've reduced the number and the intensity of infestations in a lot of places. That doesn't mean it has stopped, but this year's flowering is less than last year's in Onerahi — and that's a win because it's been daunting."

Her advice to Northlanders who cared about the natural environment was "do what you can".

"If it's flowering, you can at least stop it from podding. Then be prepared next year and get it early so there's even less chance of it podding."

Moth plant is rife in the area around Inlet Rd and Wharau Rd in Kerikeri, on private land, forest margins and council roadsides. Photo / Supplied

Kerikeri residents have also contacted the Advocate concerned about the scale of the infestation this year, especially in the Inlet Rd-Wharau Rd area.

They conceded little could be done to force private landowners to remove the pest plant but wanted the Far North District Council to set an example by removing the weed from council-owned roadsides.

The district council did not respond to the Advocate's queries about moth plant.

The Northland Regional Council, which is responsible for pest management, said moth plant was one of the region's worst weeds because it was tough, fast-growing and able to quickly smother trees and regenerating seedlings.

Pest Plant biosecurity specialist Sara Brill said the regional council did, however, not enforce moth plant removal.

"It's too far gone. We'd have to enforce every road in Northland. The cost would be enormous."

Instead, the regional council encouraged people to keep their own gardens clear and pull up any vines they saw while out walking.

If an area of roadside was especially bad people could make a request for service, online or by phone, to the district council.

Most of the regional council's support for pest control was focused on animal pests, but it could help weed groups in areas with high ecological value — by supplying herbicide, for example — or in areas where many people were working to combat a pest plant problem on private or public land.

■ Go to www.nrc.govt.nz/pestcontrolhub for more information. Moth plant is poisonous and produces a milky sap which irritates the skin so gloves should be worn when handling it.

Chrissie Stephenson about to deal to a flowering moth plant vine. Photo / Tania Whyte

How to be a moth plant warrior

The number one thing you can do is pull out vines any time you see them. But if you're keen to do more, these are Chrissie Stephenson's tips for moth plant warriors.

Start early: Pull out seedlings all year round. Go back to places where you've seen or removed a mature vine.

Late spring/early summer: Look out for the vine's tell-tale white flowers. Either pull out the vine at the root or cut and paint with Metpaste or glyphosate paste. The cut needs to be close to the ground so the paste can do its work.

January/February: By now the pods may have formed. Remove them, put them into black plastic bags with some water and seal tight. Then put the bags aside and let nature do its work – the seeds and pods will turn to mush by spring. Just don't put the pods on the green waste pile!
Next, cut or pull the vine out at the base. Again, use paste if you're cutting. Take it easy on yourself: There's no need to pull the vine from the host tree or structure. It will die once you've cut or pulled it.

Every year: Make a commitment. Go back to where pods have burst. There will be seedlings to deal with.

But most of all: It's better to do something than nothing at all.