Highland Chainsaw Massacre: The end of the rhododendron invaders in Knoydart

Highland Chainsaw Massacre: The end of the rhododendron invaders in Knoydart

Knoydart  is the first place on the Scottish mainland to declare victory against the rhododendron, an invader which threatens to strangle and kill some of the country’s finest woodlands. Richard Baynes returned to the tiny, isolated community which has become the front line in the war against one of the thugs of the plant world, to find out more.


The buzz of the chainsaw lifts to a scream as it tears into the thick, fibrous stem of the rhododendron bush.

The plant topples, the chainsaw swiftly reduces it to a pile of branches, and the smell of sour sap mingles with the exhaust of the saw and the acrid smoke from the fire.

The cut branches are dragged out of the undergrowth and piled onto the blaze. It must be carefully managed for the fiercest heat to consume the green branches.

The clegs are biting, the whip-like branches scratch and slap at our skin, and we cough as we breath in the blue-grey smoke. But the work goes on, hacking back the dense dark-green bushes.

As evening approaches we look across the a few metres progress we have made against the thicket in a day. It’s hard to see how 500 acres of the things could ever be beaten.

But now, four years after I helped out on the rhododendron clearance programme,  victory over the plants in the Knoydart peninsula has been declared. This month, for the first June in decades, the pale purple blooms can’t be seen along the shore, and the sound of chainsaws won’t reverberate around the woods.

It is the culmination of a relentless, decade-long campaign by the Knoydart Forest Trust, involving dozens of workers, and crowds of volunteers, to rid the Highland peninsula of the invasive, alien shrub, rhododendron ponticum.

The worst of the  500 acres of ponticum shrubs was in the woods around the village of Inverie – the most isolated community in mainland Britain, and accessible only by boat.

In some places they covered the ground in such blankets that nothing else could survive there. They lay elsewhere too, in pockets right across Knoydart, which lies just north of Mallaig.

Chain-sawing the bushes, burning trunks and branches, teams slowly cleared the ground, working inwards from the open hillsides outside the main community of  Inverie towards the most densely covered areas immediately around the village, until the last unwanted  rhododendron fell.

The ponticums are a major problem in the Highlands. Scottish Natural Heritage says only on the island of Colonsay – with the advantage of total isolation – has anything like this level of  rhododendron clearance been achieved before, and the Knoydart scheme could show the way ahead for dozens more.

There can be no doubting the magnitude of the achievement, with woodland transformed and the return of native species.

But despite the success, the battle to keep the rhododendrons from strangling the woodlands will go on for many years to come. It’ll be two years at least before the final part of the eradication programme, using glyphosate weedkiller to poison the cut stumps, is finished.

There will still be rhododendron ponticums in Knoydart, in pockets as yet undiscovered and in and around private gardens whose owners have refused to allow them to be removed. These could be potent sources of  re-infestation, and will have to be continuously monitored.
And the area covered is just a tiny fraction of that covered by rhododendron ponticum in the Highlands as a whole.

Tackling them is among the biggest problems facing those who care for the Scottish environment.


Grant Holroyd is the Community Forest Manager in Knoydart, in charge of the day-to-day working of the forest trust. I talk to him in the offices of the Knoydart Foundation, which ten years ago bought out the estate on behalf of the community from landlords who held it until then.

As if to emphasise the remoteness of the place, our meeting is delayed when Holroyd has to dash out to one of his staff who has broken her leg – badly it turns out – in the woods above the village. Throughout our conversation he is peering out of the office window across the rain-swept harbour to see if the lifeboat has arrived for her.

Holroyd, cropped dark hair and beard greying, came to work for the estate owners as a forester five years before the buyout, and watched in dismay as the woodland deteriorated under absentee landlords and a lack of direction.

The situation could be farcical.

“Someone arrived in a  helicopter one day and said ‘I’m the new owner,’” he says. “We just said OK, but really it could have been anyone, we had no idea who he was.”

Within days of the establishment of the Foundation, the forest trust, which had been waiting in the wings, was up and running. It is a completely separate organisation to the Foundation, as it manages some woodland on neighbouring estates, but the two work hand in hand.

Tackling the rhododendrons was one of the trust’s top priorities.

Most imported rhododendrons are harmless, but the ponticums are a problem, says Holroyd, because of their aggressive ability to invade land, especially areas recently disturbed, such as where timber is felled. Their blanket coverage provides little sustenance for native wildlife, and they poison the soil, preventing other plants growing.

Once they take over the lower storey of a wood, new tree seedlings cannot get established because they have no light. In time the old woodland trees will die, leaving the ponticum triumphant.

At first the plan on Knoydart was to contain the ponticums; for the first five years or so no one could imagine eradicating them. But then, says Holroyd, government grant funding was boosted as the powers that be began to take the rhododendron problem more seriously.

That boost led to a change of plan, towards total eradication.

Good financial management enabled the trust to keep employing people to do the work on a year-round basis, and slowly and laboriously the tide was turned.

The key component though, according to Holroyd, was the use of local people on a long-term basis.

“The other way of dealing with rhodies is to have a large forestry company employed, itinerant contractors, and as a result you don’t get any continuity. They do a good job but they won’t be here when plants crop back up again in areas they have cleared … it won’t come back to haunt them.

“The reason we have been successful is that we have got a local dedicated team and we know that if we miss one plant this year it will be obvious next year.”

The enthusiasm of local people for the scheme was boosted by the fact that decent pay was available for rhododendron clearance work that could be fitted around other jobs such as tourist businesses and fishing.

The community of little more than 100 people has seen over ten years some £250,000 spent on the rhododendron programme. It has provided steady work for two or three people at a time and a source of extra income for plenty of others.

In a place that struggles to retain its population, it has actually helped to attract people to the area too.

Community forester and rhodie cutter Danny Gorman, with a degree in forestry from Edinburgh University, is now in his fourth year in Knoydart.

His partner Angie Smith originally trained to use a chainsaw so she could cut her own firewood at home in Dunoon, but as a result became interested in forestry. The mother of two came to Knoydart 18 months ago and now works alongside Danny. The couple plan to marry next year.

“It just came about like that,” says Smith, previously a youth worker and holistic therapist. “But now it’s great to be doing the kind of work I enjoy in a place like this.”


As the weather clears briefly Holroyd walks with me to the woodland along the road south east of the village where I had laboured as a volunteer.

Even in the watery winter sunlight the open woodland is now attractive. Tall trunks soar upwards, ferns and other greenery sprout from among the mossy jumble of rocks and fallen branches, and little clear pathways run up towards the low, vegetated cliff behind.

In spring, parts of these woods were carpeted in a brilliant mass of bluebells, as bulbs dormant in the soil for decades burst into flower. Birds such as wrens, siskins, blue tits, woodpeckers and robins are now making their homes here. The transformation is complete.

“When the area was crofted,” Holroyd explains, “this was the best ground for crops and would have produced food that was actually exported.

“It was taken over as woodland in Victorian times after the estate was cleared, and that of course was when the rhododendrons were planted, and that’s where the problem stems from.”

The lush flowers of the ponticums produce millions of seeds, and the plants can spread at an alarming rate.

After the eradication programme began, ponticums were found in Glen Guiserein, a couple of miles from the village.

Worse still was the day foresters were planting trees at Sandaig, five miles away. When they peered into a small river gorge near the site they saw to their horror it was infested with a mass of ponticums. They could only be tackled by abseiling into the gorge and dragging the cut branches and trunks out to burn.


In a couple of days in Knoydart it becomes evident that while many people are, delighted with the transformation of the woodland, some are less impressed, and some dislike the methods used to destroy the rhododendrons.

Knoydart attracts idealists, and the use of glyphosate in the final stage of destroying the plants sits uneasily with some.

But in such an isolated  place it’s no use falling out with anyone when the next day you might need their help to get your new fridge off the boat, or their first aid skills on your injured child.

Tim Bowyer insists that there is no rift in the community, just a difference of opinion.

He’s a long-bearded, long-haired Yorkshireman, looking like a photo of a backwoodsman in the old American west.

He came to Knoydart to work in forestry almost 30 years ago and he and his wife Hannah have been here ever since, bringing up their two sons in a beautiful cottage just outside Inverie.

He was on the original board of the Forest Trust, and took part in the first stages of the rhododendron control scheme, but when it became a programme of total eradication he left.

Bowyer is aware of the financial benefits the eradication programme has brought, and knows that one of the reasons total eradication was insisted on was because without it the grants for the programme, paid through the Forestry Commission, would not have been forthcoming.

But he enjoys the flowers of the ponticums and the greenery the bushes provide in winter. The stems are good firewood, and he believes they could have been managed in smaller areas.

Bowyer says: “This is supposed to be a community project where everybody is supposed to be listened to. You are going to have to compromise with certain things.

“If it was an estate owned by one person he could say ‘I’m going to eradicate’ and you wouldn’t have a leg to stand on in opposing that.

“But everybody should have some input, and if someone wants rhodies round their house their voice should be heard.”

He fought to retain the rhododendrons on foundation land around the perimeter of his home, and eventually succeeded. As a forester he says he knows how to control the plants and he says there has never been a problem with them invading his garden.

It was a compromise in the end, but, he says: “It took a battle – and it shouldn’t have taken a battle.”


But battles like that between the Bowyers and the trust are one of the reasons why the job of clearing rhododendrons across the Highlands will be so difficult. Any plants left in an area could start the invasion process off again.

Steve Murphy is the Forestry Commission’s rhododendron officer, covering Argyll and Perthshire. Another officer for the Northern Highlands, including Knoydart, will shortly be appointed.

Murphy says around 12,000 acres of Argyll and Bute alone is completely covered in the plants. That will cost £10 million to clear. More than half the shoreline of Loch Lomond is covered in rhodies, and the commission believes more than half of all Highland estates have a rhododendron problem.

To add to the ills already laid at the rhodies’ door, Murphy says that the plants are a host to the phytophthera fungus, which has been implicated in the tree disease known as sudden oak death.

“The big worry is that it could get into commercials and native tree species. That would be very serious indeed.”

Murphy’s job involves coaxing landowners to co-operate in rhododendron eradication programmes, something that was less than straightforward even for the Knoydart Forest Trust, where there was one principle landowner backing the scheme from the start.

So, given the patchwork of land ownership across the Highlands, how can we best tackle the problem of rhododendron ponticum there?

Murphy believes raising people’s awareness that the rhodies are a problem – despite the attractive flowers – is essential, and landowners need to get involved in controlling them. Grants are available and a proper level of support needs to be provided.

“Collaboration and co-operation between owners is vital,” he says.

And does he believe the rhodie problem in the Highlands can ever be wholly solved?

“It will take a long time,” he admits. “But if the commitment is there we can go a long way to solving it.”



Walking back down through the woods, I ask Holroyd how he feels now about the rhodies.

“I feel kind of sorry for them,” he laughs. “When we first started the project I hated them. We would clear one small area and still be surrounded by them for hundreds of yards around.

“Then we got to the point where we knew we could beat them and my feelings changed. They’re a beaten thing now.”

But that won’t stop him continuing the campaign.

“The worry is that once you get rid of the rhodies people will all kind of forget there was ever a problem.

“Once we have forgotten about how bad it was in the past, maybe with new people coming in too, people will see a couple of rhododendron bushes popping up, they will add a little bit of colour, and they won’t be too bothered.”

If that happens the bushes will re-establish themselves and the battle will start again. And after a decade’s labour, that’s something Holroyd doesn’t want to even contemplate.






Panel 1:

Although the Himalayan region has the most types of rhododendron, the plants are found across Asia, Europe  and in North America.

The rhododendron ponticum is a native of Spain and Portugal, and some areas of western Asia. In its native habitat it is quite rare.

It was introduced to Britain in the 18th century and has spread rapidly in recent years, causing problems in upland areas throughout the UK, especially in the warmer, wetter west.

Some believe its vigorous invasive nature is due to interbreeding with other rhododendrons, and scientists have found some hybridisation with a North American plant, Rhododrendron Catawbiense, which has helped the plants survive in the colder eastern Highlands.

The standard technique for its removal is to cut the plants down, then burn the wood to leave the site clear. The stump will then produce leafy shoots; they are usually left to sprout, then the leaves are sprayed with a glyphosate weedkiller, which is taken into the root system and kills the plant.

In recent years a new method of controlling rhododendrons called levering and mulching has been developed in Scotland. This involves cutting the branches away to leave a long stump, then using it to lever the roots up; the dormant growth buds on the stump are then destroyed to prevent them growing again.






Panel 2:


Scottish Natural Heritage says if ponticums are not controlled they will take over and destroy the coastal woodlands of the West Highlands, a habitat unique in Europe.

The organisation sees the success of the Knoydart project as an example for others to follow.  Jeanette Hall is in charge of SNH efforts to control rhododendrons.

She says: “The vast majority of non-native species have very little impact on their environment …And then you get a few such as rhododendron and a few aquatic plants which are absolute thugs, totally take over a habitat and destroy all the associated species which were there before.
“The problem is not so much that they are not native but that they are so invasive.  There are a few native species which need controlling too at times – bracken, gorse, deer.

“The difference is that whereas the native ones do have a valuable place and can support a lot of biodiversity … but just get out of hand at times, the non-native ones support virtually nothing.

“I am not aware of any invertebrates that live on Rhododendron, and maybe only one or two mosses.  Otters might shelter under it but that’s not because it’s rhodie, anything else would do just as well.”

Like the Forestry Commission and the Knoydart Forest Trust, SNH believes leaving pockets of rhododendrons behind to suit individual landowners can ruin clearance efforts.

Hall adds: “You could coppice it on a two-year cycle and just about keep it in check, but it would be extremely time-consuming and costly and I can’t think why anyone would want to.  If you let it grow to the point where it flowers then it has the opportunity to spread, and if you don’t then it’s just another boring dark-green bush, so why would you bother?”