Rhodo-chop: how martial arts will prevail against flower power

Published on Saturday 12 December 2009 19:14

IT MAY not Kill Bill but it threatens to put an end to "Rhodie". Scotland's most invasive foreign invader – rhododendron ponticum – is facing death by martial arts.

The exotic plant, imported by Victorian landowners to decorate their gardens, is now so widespread and damaging to native wildlife that it is considered a pest.

Nicknamed "Rhodie", it has continued to flourish despite efforts of pest controllers to cut it back with chainsaws and smother it with harmful chemicals. Tens of millions of pounds has already been spent in Scotland trying to curtail the spread, with little impact.

But two plant control experts have now come up with a new method to peg the problem bush back using a martial arts-style attack that renders it lifeless within minutes.

The technique, devised by Gordon French and Donald Kennedy from Morvern Community Woodlands, is described as being a cross between tai chi and karate. Supporters say it offers a cheap and effective method of battling an intractable enemy.

The pair carefully examine each rhododendron bush, work out the direction in which its stems are growing, before twisting their bodies around the plant and snapping it in exactly the right places. With minimal effort, the rhododendron is reduced to a pile of leafy waste. Within hours, the duo claim, whole swathes of the invader within woodlands can be destroyed while hardly breaking a sweat.

Robin Payne, the invasive species expert at government agency Scottish Natural Heritage, said he was amazed when he saw the technique in action.

"Normally people just chop rhododendron down and it grows back again even stronger," he said. "Gordon and Donald came up with this technique which is tai chi and karate meets invasive species control.

"They twist and move their bodies and it looks like a kind of martial art. They look at the plant and know which way to bend it and which stems to snap to destroy it. After they have finished it looks like it has been decimated. There are lots of dying and rotting rhododendrons all over the place."

He is hopeful that finally a way to quickly and effectively kill rhododendrons could have been found, without even needing to use chemicals.

"This is the number one problem in Scotland as far as plants go. If you think of a non-native plant that poses the most threat to biodiversity it's got to be rhododendron."

Payne is advocating that a network of rhododendron destroyers should be set up to take on the invader.

"There's an art to it, which Gordon and Donald can teach," he said. "Like a martial art, you have got to learn from a master."

Rhododendron ponticum is native to China and Mediterranean countries such as Spain and Portugal, and was brought to Scotland because of its distinctive purple flower, which blossoms once a year.

What previous generations of gardeners did not fully understand was that in the right locations the bush can grow up to 15ft high, smothering habitats and threatening the existence of native species.

As well as shading large areas to cut out light for other plants to grow, the bush poisons nearby soil with chemicals that kill other species. Its fallen leaves acidify the soil, reducing earthworm numbers. It is also a host for a new disease, phytophthora, more commonly known as Sudden Oak Death.

Around 11,000 acres of Argyll – an area larger than the size of Aberdeen – are covered in rhododendron ponticum as well as a further 10,000 acres in the Loch Lomond and the Trossachs National Park.

French, 53, has already used the technique to destroy plantations of rhododendron ponticum on the Morvern peninsula on the west coast of Scotland where the plant runs wild.

Using chemicals was a mistake, he said, as the plant eventually recovered. "The best remedy we have got is our bodies," he said. "Used in the right way that's all you need. It's all about understanding the plant and exploiting its weaknesses."

He believes the plant may have met its match. "You can do it at far greater speed than using a chainsaw. We want this thing stopped in its tracks before it turns into a monster."

Dr James Merryweather, from the Skye and Lochalsh Environment Forum, is helping to popularise the technique by putting together leaflets, giving talks and creating a website.

"We know that rhododendron is a devil to get rid of," he said. "But they (French and Kennedy] have taken a very different view of how to deal with it, a mechanical view based on the way it's constructed. When I watched them doing it I was absolutely gobsmacked."

In contrast, he said, using a chainsaw to try to control the pests was ineffective. "You cut them down to ground level, but then they sprout again. Then you go in with herbicide and make a terrible mess. It takes about three times as long, and costs twice as much."