Dave Hansford

Wilding pines

Pinus contorta, a native conifer of North America, was deliberately seeded through swathes of high country and conservation estate as a counter-measure to erosion. These rugged self-seeding trees and other stray exotics now infest hundreds of thousands of hectares throughout the country.

Written by       Photographed by Dave Hansford

For a moment, Gilbert Seymour had the world at his feet. He’d just climbed Mt Cook with legendary guide Harry Ayres, and from the summit he could look back down the sweep of the Tasman Glacier to his pride and joy, the 8000 golden tussock hectares of his high-country run, Ferintosh Station.

“The fifties were the best times around here,” he says. “There was a lot of money around, and it felt like anything was possible.” He went out to prove it by flying solo over the summit of Cook, making him, he suspects, the only climber to both climb and fly over the peak.

We chat between sips of coffee and bites of Shrewsbury biscuits. Seymour cut a gap in the windbreak around the homestead, so he can gaze upon his mountain any time the clouds part. It could well be the grandest view from a patio anywhere. “No two days are ever the same here,” he says, regarding Aoraki with a look some of us might keep for a lover.

Ferintosh lies with its back against the Ben Ohau mountains and its feet in the glaucous reaches of Lake Pukaki. His father bought the place in 1935, and Seymour spent his school holidays here. Apart from a couple of years mustering on a nearby station, he tells me, “I’ve lived here all my life”.

He worked Ferintosh to a keen edge, running 3500 merinos and 150 head of cattle. He developed the easier lakeside flats and gradually retired the ramparts of the back country. It hardly felt like work.

But the world outside was changing. Seymour had never seen Auckland, but it was about to change his landscape, his life, forever. The sprawling city’s hunger for electricity saw the Ministry of Works commission a hydro dam on Lake Pukaki. When it closed the gates in 1952, the rising waters claimed 800 hectares of Seymour’s best country. There was no compensation.

Gilbert Seymour has watched his beloved Ferintosh Station, on the shores of Lake Pukaki, be over-run by wilding Pinus contorta and Douglas fir. In the 80s, he spent $20,000 on digger hire to claw the trees from the ground. Within weeks, “young pines were coming up between the windrows”.
Gilbert Seymour has watched his beloved Ferintosh Station, on the shores of Lake Pukaki, be over-run by wilding Pinus contorta and Douglas fir. In the 80s, he spent $20,000 on digger hire to claw the trees from the ground. Within weeks, “young pines were coming up between the windrows”.

Progress took no pause. A second dam in 1976 raised the lake another 37 metres, swamping the few flats Seymour had left. This time, he got some recompense, “but it was a battle all the same”.

In no time at all, the clawing waves began dragging the shoreline—now steep and exposed—crumbling into the lake, so the ministry planted trees to hold it. Its staff sowed thickets of Douglas fir, and a hardy, gnarly conifer called Pinus contorta—the lodgepole pine. Seymour would come to despise the very name.

Contorta is a native of North America, honoured as the provincial tree of Alberta, Canada. Introduced to New Zealand in 1880, it is a tenacious coloniser of loose steeplands and can cope with pretty much anything, which is why it caught the attention of the New Zealand Forest Service in the 1950s.

Soil engineers had long been dubiously eyeing the scree fans tumbling in rocky aprons down the New Zealand high country, and were convinced that introduced browsers—deer, goats, rabbits—were the cause. The answer, it was decided, was to hold the slips with exotic trees.

Contorta was their first choice—by 1955, they’d planted 8000 hectares of it—but they also planted Douglas fir and Corsican, Scots and Ponderosa pines, among a dozen others.

At Lake Pukaki, just as soon as the contorta were old enough to grow viable cones—around six years—their seeds started floating onto Ferintosh; 15,000 from each tree, each year.

Seymour and I take a drive along the lakeshore road that marks the eastern boundary of the station.

As we crest a rise, we come upon rank after tangled rank of contorta, writhing in impregnable thickets across the slopes.

“Is that the plantation that infested your farm?” I ask.

“That,” he says evenly, “is my farm.”

Seymour is now 84. By rights, he should be sitting on that patio, savouring the country he worked so hard. But most days, he and his wife throw a scrub bar and loppers in the back of the Land Rover and do battle, trying to stop contorta stealing their life’s labour.

The blight at Lake Pukaki, which has since spread over many thousands of Mackenzie Country hectares, is testament to the sheer weediness of trees like contorta, which can hold viable seed in cones for a decade. Botanists noted back in the late 1800s that some conifers were already jumping plantations. Thomas Cheeseman wrote that seven introduced trees were all reproducing themselves “very freely” in “most parts of the Dominion”.

They rode the wave of land clearance, marching across New Zealand in the wake of the axe and the plough. Today, stray exotics (known as wildings) have seized an estimated 800,000 hectares of the South Island alone—two-thirds of that lies under contorta.

Many infestations lie in plain public view, but “legitimate” pine plantations have become such a familiar sight to New Zealanders that few would distinguish the stands that greet them, for instance, as they drive into Twizel as one of the country’s costliest and most destructive pests. Certainly, visitors from North America or Europe would think little amiss, especially when a sign at the head of Lake Pukaki welcomes them to the “Town of Trees”.

Thousands of them drive past Ethan Gabriel’s gate every year on their way to Mt Cook. “They come here to see iconic New Zealand,” he says, “and the irony is that they may as well be looking at Wyoming or Montana.” Gabriel is a neighbour of Gilbert Seymour. His spread, Pukaki Downs, has also been infested—at frightening speed—by the same Ministry of Works plantation. “What’s sad is when I first came here, it didn’t look anything like this. In just five years, it’s gotten to the point where I feel a bit hopeless with it, to be honest.”

DOC forester Brad Lett on his way to the next pine in Kaweka Forest Park. Despite the risks and the costs, the use of helicopters and this “human sling” has so far proven the most cost-effective way to take the fight to scattered trees in difficult country.
DOC forester Brad Lett on his way to the next pine in Kaweka Forest Park. Despite the risks and the costs, the use of helicopters and this “human sling” has so far proven the most cost-effective way to take the fight to scattered trees in difficult country.

Many of the big wilding stands around here are pretty much all the same height—all the same age class. Some will tell you they sprang up in 1997, after farmers illegally released rabbit haemorrhagic disease. Prior to that, they reckon, one pest was at least helping contain another.

“I’m a forester, not a farmer,” grumbles Gabriel as he hefts a scrub bar out of his ageing Land Cruiser. “Sometimes I’d swear, when I look at these seedlings, that they’re giving me the finger.” Like Seymour, he’s exasperated by central Government’s unwillingness to take responsibility for the trees it planted.

Instead, Gabriel and his neighbours have teamed up with Environment Canterbury and the Department of Conservation to form a trust to tackle the trees from their operational budgets—righting an historical wrong that should be paid out of the consolidated fund, rather than burning up valuable conservation dollars. Similar coalitions have sprung up in Marlborough, Ohau, Queenstown and Southland.

Pete Willemse, a DOC programme manager at Twizel, says contorta grows “probably five to 10 times faster” in the Mackenzie Country than in its native North America. “You get a lot of water storage from snow in the winter and then, in the heat of the summer, they grow like buggery.”

Such monocultures leave land worthless, he says. “Farmers can’t put sheep on it, so not only do they lose that land use, but they lose the value of that land too; they can’t sell it. It’s a liability.”

Contorta has no value as timber, and it’s just too much hard work and costly transport to return a profit as firewood.

Wildings also steal thousands of litres of precious water, denying pasture and stock. But that’s not all, says Willemse. “Most people don’t realise that if we let the Ohau Range continue to be infested with wilding trees, you can say goodbye to half the recreation that happens in this town. The water sucked up by the trees would be so great, there’d be no water table. The creeks would dry up; there’d be no fishing. Looking a long way down the track, we might just have a bigger lake-level problem with our electricity than we have now.”

But his immediate concern is the larch, Douglas fir and contorta strangling conservation lands in the Mackenzie Basin. “You lose all the native plants which are out-competed by the forest, plus those that would have lived there otherwise. Then there are all your invertebrates, your birds and all the other native animals being displaced.”

But the Mackenzie Country is far from alone. In the North Island, wildings now plague the Kaweka and northern Ruahine ranges, where they are a major conservation pest. A further 150,000 hectares of land around the Napier-Taupo highway is infested from plantings in Kaingaroa Forest, and a relict stand at Karioi Forest near Ohakune constantly threatens Tongariro National Park and the Kaimanawas.

[Chapter Break]

Of all the ways to seriously hurt yourself, the chainsaw and the helicopter must be two of the most murderous. Yet here, high upon the craggy greywacke ramparts of the Kaweka Range, Eddie Te Kahika’s wilding pine team put in long workdays with both. And just for a bit of frisson, they spend much of the time hanging, 100 metres in the air, on a chain beneath a Hughes 500D.

The “human sling” team is hand-picked from dozens of hopefuls in DOC ranks. Around here, every man and his dog has a chainsaw ticket, and plenty of them know how to behave around helicopters. Te Kahika looks instead for an even temperament. “Up here, you’re going to end up in situations you don’t like. We need guys who are going to keep their head.”

Today, six of the team are picking off single, scattered contorta peppering the regenerating hills above the Napier–
Taihape road. In this group, Te Kahika found what he was looking for; the mood, even at 5 am, is jocular, but the checks are fastidious. Carabiners, harnesses, helmets, radios
—everyone checks everyone else’s gear. As the chopper appears over the hill, clattering in the brittle morning air, all the workers start their chainsaws in one last test.

Te Kahika’s not about to let some townie blot his safety record. He takes the single carabiner that fastens the top and bottom halves of my full-body harness and binds the release clip with electrical tape. “That’s so you’re not tempted to play around with it. Undo that, and it’s all over.”


I learn the semaphore that will tell the pilot whether to lift me or leave me. Everything is kept simple and standardised. There are just a handful of radio calls and everyone has to talk the same language.

Without drama, the team step up to the pad, grab the 15-metre chain and clip in. Their practised demeanour makes what is, to terrestrial mortals, a pretty exhilarating concept—a human being snatched high into the air to swing like a plumb bob—an almost workaday thing.

My headphones crackle. “OK Dave, you’re up.”

It’s a doddle; Spence Putwain, the pilot, practically puts the heavy metal ring in my hands. I clip the carabiner through, and, still only dimly satisfied that I’m prepared to trust my life to it, extend my right arm for a thumbs-up (remembering, like I was told, to turn it horizontal so the pilot can see it).

The moment your feet leave Earth, where you made choices, took leads, directed your destiny, you become again a helpless, directionless and very vulnerable child.

Putwain throttles the Hughes up and over the bucking ridges, and the wind threatens to tear off my earmuffs. The Kawekas speed to a blur. I’d appreciate the view were my eyes not streaming.

This is not soaring; this is exactly what it looks like—being dragged through space. The racket of the chopper, the rotor wash, the wind, and the somehow incongruous banter of the team in my headphones turn the dream of flight into something closer to a restless night.

Te Kahika has picked me an easy first landing, and a flattish, bare clay pan rises to meet my feet. I unclip, give the semaphore, and remember to watch the flailing metal ring, which departs—with all the noise and tempest of the rotors, the reek of jet fuel—to leave me staring into the face of the enemy.

This is contorta ground zero, where the Forest Service tipped sacks of seeds out of aeroplanes in the 50s and 60s to control erosion. The Kawekas nourished the seeds to vigour and fecundity beyond even its native Americas, until it infested nearly a quarter of the 60,000-hectare park. Now I’m standing next to one of their millions of progeny.

“There are parts of this range where you’d swear you were walking through a production forest,” says Te Kahika. For someone who’s been battling the wretched tree here for 25 years—he was one of the pioneers of the human sling—he’s magnanimous towards his forebears. “They had good intentions; they thought they were controlling erosion. The plan was to plant up the slips in areas of concern and to contain any seed dispersal, but they just couldn’t keep up with it—they just let it go.”

He gazes out over the hills, ironically marred by huge slip scars—turns out slips are a perfectly normal part of the New Zealand geography, with or without contorta. “The Kawekas were burnt, grazed with merino sheep, then the pests arrived—the rabbits, possums, Sika deer, red deer, goats, wild cattle. The park got an absolute hammering, and then contorta came along…it’s been devastated.”

On my scrubby ridgetop is a single contorta, maybe 12 or 15 years old. It’s hard to tell how fast they grow at this altitude, but they’ve been found atop 1700 metres, which means there’s nowhere in the park they can’t colonise. The ground is littered with small cones, like bullet cases at the scene of a crime. The helicopter appears over the ridge, with Mark Lewis dangling below. He gathers up his chainsaw before landing like a dancer, deftly unclips and sizes up the tree.

These singletons aren’t normally very big, he explains, but this one is going to be messy—a tangle of branches spread like a crown of thorns almost from ground level, where rocks wait to blunt Lewis’s saw. “The Sika stags rub these trees with their antlers to shed velvet,” he explains. “When they break the main trunk of a young tree, it grows back as one of these mongrels.”

He cuts his way in, gaining access to the trunk, which topples off over the ridge. Then he digs by hand all around the trunk. Leave too much stem—or a single needle—and contorta, like the hydra, just grows more heads.

Aotearoa, or Alberta? Wildings, such as this infestation of contorta at the head of Lake Pukaki, are stealing our very identity. “Before long, this place is going to look like North America,” says local farmer Ethan Gabriel.
Aotearoa, or Alberta? Wildings, such as this infestation of contorta at the head of Lake Pukaki, are stealing our very identity. “Before long, this place is going to look like North America,” says local farmer Ethan Gabriel.

Lewis is among the oldest of the human sling team. He’s been doing this for more than 10 years, and says the trick is to stay focused. “We all want to go home at the end of the day,” he says. “You have to keep your wits about you.”

Sometimes Putwain drops them onto bluffs so steep they have to stay clipped onto the chain, or “cut on the run”. “That’s when you can’t afford any mistakes,” says Lewis. “If you bring the tree down onto the chain, you’ll pull the helicopter down, and you with it.”

Even a man on a sling can’t reach some of the perpendicular places contorta will grow. That’s when Brad Lett gets his rope out. Another of the team’s veterans, he’s the abseil specialist, lowering himself down sometimes overhanging precipices to tackle a tree. The risks in wielding a chainsaw next to the rope that keeps you tethered are obvious.

“Dangling under the helicopter is the safe part,” says Lett. “It’s when my feet touch the ground that I know I have to be extra careful.”

The team make their way across the faces, battling through recalcitrant leatherwood, pulling seedlings by hand and chopping the bigger trees. Meanwhile, Te Kahika is in the chopper, spotting for his team on the sling, looking for wildings and co-ordinating the drops and pick-ups.

But there’s only enough money for containment, not eradication, so all the team can do is try to stop contorta infesting surrounding lands, such as the Ruahine Forest Park to the south. They work a four-year rotation, patrolling the boundary and lopping any new trees before they’re old enough to set seed.

Te Kahika has run into the same funding problems that beset wilding control operations country-wide, and he’s come up with the same response. “We’ll mimic the South Island model,” he says, “and get local agencies together, creating a united force to push for more funding.”

Like everybody else, he’s frustrated by central Government’s indifference and parsimony. “They need to realise the destruction and damage that’s going on. It’s unfortunate that we have to make a hell of a racket before somebody even turns their head.”

The trouble is, he says, that there’s nothing cute about a contorta. While millions get poured into saving kakapo, wildings go on stealing our natural heritage metre by inexorable metre. “Contorta is a silent monster; every day, it just grows. People need to stop and think about it, and take responsibility for what happened in the past.”

Putwain swings the chain into my grasp, and I’m aloft again, looking back over the killing fields. For every fallen tree, another thousand seeds lie beneath, waiting for their turn in the sun.

[Chapter Break]

In the South Island, parts of the Marlborough Sounds are over-run. Corsican pines from Hanmer Forest have invaded the Amuri Range and Molesworth Station. The headwaters of the Branch River in southern Marlborough are also heavily infested, and the hills above Queenstown are almost a solid stand of wildings. They even spring up on Stewart Island dunes.

According to Nick Ledgard, around a third of infestations are escapes from plantation forests. Another third stem from farm plantings such as shelterbelts, and the remainder, like the invasion of the Craigieburn Range, come from Government erosion-control plantings. A senior scientist at the Scion forestry research institute, Ledgard is an expert on wilding control, not least because he planted some of them as a Forest Service trainee 40 years ago.

“The need for those early erosion-control plantings was not as great as we perceived in those days,” he says, adding that we now understand that much of the erosion in our hill country is the result of earthquakes, uplift and shearing, an entirely natural state of affairs.

Ledgard insists the plantings had value. “But the problem is, they didn’t stay where they were put,” he says. “We certainly backed the wrong horse with contorta. We woke up to what was going on a bit late—tried to close the door after the horse had bolted. Now you’ve got situations which are going to cost millions to get on top of.”

Some woke earlier than others. Ridgway Lythgoe spent five years in Tongariro National Park as a Lands and Survey ranger in the 70s and 80s. He remembers looking at that contorta plantation at Karioi. “I recall these long tentacles of pines clawing their way up the ridges. They were already reaching up to the Round the Mountain Track.

“I was concerned, but not everyone thought the pines were an issue. Some believed they’d reached their altitudinal limit.”

They hadn’t. Contorta is unfazed by frost, laughs at snow. It has since been found high on Mt Ruapehu. By 1978, says Lythgoe, tramping club volunteers were travelling from all over the North Island to pull pines.

“I took those groups out. I’d be on a chainsaw all weekend, taking the big ones out, while other people were dragging them away. Others were hand-pulling the smaller ones. I can remember coming home absolutely buggered on a Sunday afternoon, and looking back at what we’d done. We hadn’t moved outside of a one-hectare space. We weren’t even keeping up with the problem—the pines were outstripping us.”

A couple of years later, a little Government funding came through, and Lythgoe found himself perched on the skid of a Hughes, “a chainsaw in one hand and a pair of loppers in the other”.

“We’d sit on the outside of the helicopter with our feet on the skids—we weren’t tied on or anything—and fly around pointing the trees out to the pilot.

“He’d drop one of us off, and then he’d fly away with the others. We’d chop the trees down, then sit and wait for him to come back. When I think of it now…we didn’t have helmets, harnesses—it was quite a thrill.”

But as fast as the Lands and Survey Department was trying to control the pines, the Forest Service was sowing them. Lythgoe used to lead his volunteers into the park through the Karioi Forest, where, he recalls, “there were all these signs saying ‘Pine cones’ and pointing to a collection site”—pine cones destined for aerial drops over the Ruahine and Kaweka Ranges.


Nobody plants contorta any more as it’s been outlawed by most regional councils, but the Government’s stance on wildings is as chaotic as ever.

Mid Dome is a tussock upland complex rising from the Garvie Range in northern Southland, where it towers above State Highway 6 between Invercargill and Queenstown. In 1947, when the Soil Conservation Council feared it might slip down onto the road and railway, they started planting Pinus mugo—mountain pine—and contorta. Between 1950 and 1980, they planted 250 hectares of shingle fan on Mid Dome’s western face, after assuring public meetings that the pines would be easily constrained.

Today, wildings from that single source threaten some 80,000 hectares of tussock and farmland, from winged seeds—99 per cent of them contorta—carried up to 40 kilometres on howling nor’westers across the Mataura watershed.

Left unchecked, it’s reckoned they could eventually smother 200,000 hectares.

“The only thing that’s going to stop these bloody things is the Pacific Ocean,” says local farmer Gene Marsh, looking out across the ranks of pines crowding out his Perendales. He figures they’ve claimed around 30 per cent of his summer grazing and cut his stocking levels by 20 per cent.

To the north, on land now owned by the Ministry for the Environment (MfE) and Land Information New Zealand (LINZ), the original planting clings obstinately to the hillside, flinging seeds by the billion into the skies each season. So far it’s defeated chainsaws, scrub bars, sprays—even giant mechanical mulchers on tracks. As long as this pestiferous seed bank remains, the Mid Dome Wilding Trees Charitable Trust can only hope to pick off its thousands of progeny—year after laborious year.

Trust chair and Southland regional councillor Ali Timms is steamed. The Government owns the pines—and is responsible by dint of history for their planting—but has five times denied the trust funds to control them. The trust itself is a response to that obdurance, a coalition formed in 2007 of DOC and Environment Southland, backed by LINZ and MfE, which have given funding commitments from their own operational budgets.

But a $9 million, 12-year control programme for Mid Dome is still $3 million short, and now central Government has thrown another curve ball at Timms. Under provisions in the Emissions Trading Scheme, the trust could, perversely, be held liable for $3 million in deforestation penalties if it removes any more pines.

“That’s our funding shortfall,” she says, as we climb the hill in a bucking Hilux. “We’ll have to spend that money on carbon credits, instead of taking trees out of Mid Dome. If we’re held liable for these trees, we’ll just be forced to walk away. And that would be a tragic waste of all the years of work, not to mention the money, that has been put into Mid Dome.”

As befuddled climate change policy hobbles the control of wildings, the phenomenon itself is giving them a shot in the arm. According to a 2006 MfE report, contorta is enjoying the warming weather. “Seedlings of Pinus contorta appear to now grow faster than previously,” it notes.

Ethan Gabriel mops up wilding seedlings on Pukaki Downs Station. “I really like trees—they’re beautiful things, living things. These are just in the wrong place. If I thought too much about how they’ve spread all over the place, it would do my head in.”
Ethan Gabriel mops up wilding seedlings on Pukaki Downs Station. “I really like trees—they’re beautiful things, living things. These are just in the wrong place. If I thought too much about how they’ve spread all over the place, it would do my head in.”

In colder times, seedlings at Rangitaiki Frostflat were routinely hit by frosts any month of the year. DOC used to treat them every four years, but now has to tackle them every three. “The size of average three-to four-year old trees now look more like former five-year-old ones,” reads the report. “It is possible that these trees will start coning earlier.”

But gazing from the summit of Mid Dome over the tussock heights, east towards Cattle Flat, you might wonder what all the fuss is about. There are native Spaniards here, dracophyllums—the usual sub-alpine botanica, but precious few contorta.

DOC botanist Graeme Miller simply smiles and draws back a tussock clump. Nestled in the lee is a contorta, maybe 20 cm high. Pick a tussock—any tussock—and you’ll find another, and another, and another. Ali Timms starts pulling out those she can, but contorta stakes its claim with a deceptively deep, stubborn tap root.

Already, these are at the limit of hand control. After that, it’s a job for loppers, and not just garden-centre budget jobs. Miller is wielding an industrial-scale pair as he explains that anything less than ruthless execution simply makes a contorta mad. You have to sever the trunk right at ground level, which is why scrub bars are impotent in the sort of stony country contorta loves.

Even the most dedicated weedie can’t walk to every tree; contorta will grow on bare rock halfway up a cliff. That’s when you need a healthy budget, a good chopper pilot and plucky workers, because some control techniques are not for the timid.

The trust cleared nearly 40,000 hectares at Mid Dome, much of it hopping on and off the skids of choppers. Around Twizel, Pete Willemse’s crews worked from jump seats mounted on the skid of the helicopter, until the Civil Aviation Authority outlawed the practice last year. The ruling is up for review, but Southland chopper pilot James Hore says accidents were waiting to happen. “With so many people doing weird and wonderful things, someone was going to get hurt.”

Besides, there’s a better way, he reckons. He shows me photographs of dead trees in Skippers Canyon. They were sprayed using a single, forward-facing wand fixed to the chopper, long enough to get the spray out of the rotor wash. The pilot simply pushes a button on the joystick to give the wilding a shot of herbicide. It’s centimetre-precise, avoiding a repeat of the disastrous spray drift off Mid Dome in 2004 that destroyed crops in a 24-kilometre radius.

“In country this steep,” explains Hore, “if you try and spray something from above, the rotor wash just blows it all in a big stain down the hill.” The wand, however, “is very, very surgical. You can target exactly what you want, and it uses very low amounts of chemical. We can take one tree at a time, with just one man.”

Back in Twizel, Pete Willemse has been testing a similar device, except that his is wielded by a crewman, who either drenches the tree’s foliage or wipes a “swatch” of poison against the trunk, depending on the situation. He says the wand is the future of wilding control. “In the time it would take to drop someone off to cut one tree, I could do 10 to 12 trees spot spraying—it’s so much more efficient.”

Boom spraying, where herbicide is dispensed through transverse booms either side of the helicopter, still has a place in treating thick infestations. But getting the spray to penetrate the wildings’ canopy deeply enough to do any lasting damage has proven tricky—that’s when the downwash of a powerful chopper comes in handy—and trees have bounced back from spraying after a season or two.

A bigger problem is the waxy cuticle that protects the needles of conifers like contorta from desiccation and frost. Turns out it’s also good at blocking herbicides. Contractors have tried adding all manner of ingredients to sprays in a bid to cut through the trees’ defences, but it wasn’t until January this year that they claimed a victory.

A ruinous legacy of misguided management, wildings cost ratepayers, landowners and agencies millions of dollars every year, simply to try and contain their spread. While DOC and LINZ have put up their own money, central Government, although responsible for unleashing them in the first place, stubbornly refuses to stump up for their removal.
A ruinous legacy of misguided management, wildings cost ratepayers, landowners and agencies millions of dollars every year, simply to try and contain their spread. While DOC and LINZ have put up their own money, central Government, although responsible for unleashing them in the first place, stubbornly refuses to stump up for their removal.

After four years of trials, a simple vegetable oil added to a cocktail of herbicides appears to have finally killed a stand of Douglas fir above Queenstown. This time, the trees in a perimeter ring sprayed four years ago stayed dead, and their corpses have been left standing as a net to try to catch seeds floating from the centre of the stand. The brew’s developer, Peter Raal, says it has also killed a few contorta, though more trials are needed.

The spray affords cost savings that could tip the odds back in favour of cash-strapped control agencies. According to local DOC ranger Jamie Cowan, conventional treatment would have taken $5000, three days and six people to treat a hectare. “I can do a hectare now in seven minutes at a cost of $650, so it’s a massive, massive change,” he told TVNZ.

Raal says the spray could be the gamebreaker everyone has been hoping for. “I would never say wildings are a winnable war, given the nature of weeds, but we can certainly expect to win some battles now.”

Willemse has 10 working years left. He’s promised himself that in that time, he’ll have wildings beaten on DOC land in the Mackenzie Country. Already, he’s driven them from much of the Ben Ohau, and this season he’ll clean up the Benmore Range by exploiting contorta’s one Achilles heel.

Contorta seed on the ground is viable for only three to five years,” he says. “It’s not like gorse, where you’ve got 90 years of seed bank sitting in the ground. So it’s actually winnable.”

But deliverance—if it comes—will come too late for Gilbert Seymour. He’s battled wildings for 20 years, and the taste of defeat is bitter. “Nobody wanted to know about them; now it’s too late. We’ve lost half our grazing.” He takes a long look across Ferintosh Station. “It’ll never be like it was when I first saw it.

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