Featured in Capital #81. Subscribe to get the real thing here.
There’s a slow creep of well-grown beards spreading through Wellington and the Hutt Valley. No, it’s not gentrification, it’s Clematis vitalba! Tessa Johnstone looks into our gnarly weed problem.
I took botanist David Bellamy seriously when he sprang from a bush and yelped in his signature lisp: “Old Man’s Beard must go!”. That 1989 Department of Conservation campaign raised awareness of the invasive weed, and its potential to overwhelm native vegetation. Ever since I’ve kept a diligent eye out for its smothering creep.
So I was alarmed to notice recently that it was gaining a stronghold in Wellington’s green spaces. Over autumn and winter the fluffy white seed heads for which it is named could be seen growing in straggly patches and sometimes great plumes around the city – growing on the fringes of nature reserves in Island Bay, on the barbed wire fences around the old Tip Top bread factory in Newtown, in the overgrown gardens of rundown rentals. During Wellington’s iNaturalist City Nature Challenge in May, which saw nature lovers logging nearly 7500 observations of plants and animals from around the city, it was the second most commonly observed plant, trumped only by the ubiquitous kawakawa.
Old Man’s Beard ain’t any old weed. It’s a woody climber with stems up to 20 metres high – a single plant can cover an area the size of a tennis court and, left to thrive, it eventually overwhelms trees and causes canopy collapse.
Thankfully, I’m not the only person that’s noticed we’ve got a problem.
“Anecdotally and visually, it seems worse,” says AJ Hawkins, one half of community conservation group Old Man’s Beard Free Wellington. He too traces his aversion to Old Man’s Beard back to David Bellamy – “It’s culturally ingrained in Generation X so I was pretty primed for it.” Hawkins was roped into clearing a patch of Old Man’s Beard in Tanera Gully by his friend Nigel Charman back in 2017, and the pair have been fighting its spread around Aro Valley ever since. He takes the battle personally: “I have quite a strong emotional response to it sometimes, it’s like botanical vandalism. If it’s not addressed, you’re going to have hillsides that are held together by weeds.”
Nigel and AJ, with the help of a few other hardy volunteers, have now cleared more than 1000 plants. The plants can be so big they earn themselves names like the Norway Monster (named of course after the infamous street) and can each take several weeks to clear.
“It looks like something you’re not going to be able to achieve,” says Nigel, “but you chip away at it. Every year you do a bit more, chop it down to the trees, then down to the roots. They come back, you chop them again – slowly you get to it.”
But the work they’ve done is just a fraction of what needs doing – there are 40 sites just in Aro Valley that they could be working on, and they’ll only get through a few this year.
“It does have the potential to be disheartening when you look at how much there is to do,” says Nigel, “but if you flick it round and look at how much you’ve already done, that’s pretty awesome.”
They are not tackling this scourge alone. Up the line, Upper Hutt Busters of Old Man’s Beard (UH BOMB) are doing the same. The group has now cleared the weed from more than 100 hectares of native bush. Their first site in 2015 was two hectares of bush on steep, rocky terrain on the escarpment north of Silverstream Bridge and clearing it took more than 200 hours. But it’s worth it, says UH BOMB coordinator Chris Cosslett.
“When you look back at where we started, and there’s this beautiful face of bush there now, and you see kererū, and resident kārearea, and we meet whiteheads in flocks on that face every time we go in there. If we hadn’t done that, that bush would have just disappeared and those birds wouldn’t be living there.”
Cosslett started clearing Old Man’s Beard after noticing it smothering regenerating native bush alongside State Highway 2: “I’m a person that gets upset about these things and has to do something.”
He connected with the Upper Hutt branch of Forest & Bird, which paid him out of its own reserves to start managing the problem with some volunteers. They now have community funding for the project, and Cosslett says the combination of volunteer and paid labour is a model that could work elsewhere. Certainly, it seems that a different approach is needed. A recent report from the Parliamentary Commissioner for the Environment on New Zealand’s invasive weed problem pointed out that we don’t have a national policy on pest weeds, there’s no coordination on managing the problem, and it’s a serious threat to forests.
Wellington, Hutt City, Upper Hutt, and Greater Wellington councils all have different policies on controlling Old Man’s Beard; the patchwork approach on weeds that care little for territorial boundaries is contributing to the problem.
“The results of the different approaches are clear for everyone to see,” says Cosslett. “Travelling from Upper Hutt to Wellington there’s no doubt when you’ve left Hutt City and you’re entering Wellington city, because suddenly there it is, all up above the motorway. It’s really disheartening.” Greater Wellington say as the plant is now long-established and widespread, it’s not an effective use of their budget to attempt to control it everywhere.
Wellington City Council has a site-led approach, they control it on sites of ecological significance, but they only have the budget for weed control in 11 percent of their parks and reserves. Even on council-owned property such as road reserve, they won’t touch it. Wellington City Council biosecurity advisor Illona Keenan says it would be great to have more resourcing for pest plant control but councils won’t be able to address the issue on their own.
“We need everything in weed control. Weeds don’t respect boundaries. We need people to look after their gardens and pathways, to volunteer in reserves. Council needs to support those volunteers. All parts of council need to think about the management of our areas, and we also take a longer-term view in terms of cost.”
Chris reckons the job is now too big to be solved with manual labour alone: “I see our job as keeping the bush alive while we wait for an effective biocontrol agent. It wouldn’t eliminate Old Man’s Beard but it would reduce its vigour so that it doesn’t dominate the bush.”
Such an agent may not be far away. Horizons Regional Council and Manaaki Whenua Landcare Research have just released a microscopic eriophyid mite in Taihape, which they hope will eat enough of the leaves and buds of Old Man’s Beard to stunt its growth.
This will be New Zealand’s fourth attempt at introducing biocontrol for Old Man’s Beard. A leaf-mining fly and a fungus both failed to take hold. And the third agent, a sawfly, was also thought to have failed, but was recently spotted alive and well in Nelson after 20 years under the radar. Manaaki Whenua Landcare Research scientists are now nurturing communities of the sawfly in the South Island in the hope of distributing it to other parts of the country; and the eriophyid mite is showing promise too.
In the meantime, the same community effort that’s buoyed Predator Free 2050 is needed for weeds. “Predator Free 2050 is great,” says Chris, “but the birds have got to have somewhere to live and something to eat, so it’s all part of the same story.”