The Victorians loved its impressive clusters of white flowers, massive leaves and thick, towering stalks, while its Caucasus Mountains origins offered an exotic twist to their ornamental gardens.

Giant hogweed may have been all the rage in the 19th century, but few Victorian gardeners could have suspected they were cultivating a monster that would go on to invade riverbanks, pastures and wasteland the length and breadth of the land.

For years landowners have waged chemical warfare on the pesky plant, known for its toxic sap that can burn and blister the skin and even cause blindness, but with little major success.

Now, however, it appears the solution to tackling one of the country’s most loathed of noxious weeds may have been quietly grazing in the local farmer’s field.

A flock of two dozen sheep has been drafted in to a half mile strip of woodland near the River Deveron close to Macduff Distillery, to chomp their way through the huge weeds.

Their deployment follows an earlier successful experiment carried out nearby by the Scottish Invasive Species Initiative (SISI) which revealed that far from suffering any ill-effects from chewing on toxic giant hogweed, the sheep preferred it over grass.

The experiment also revealed that cattle and deer also seemed to tuck in with no obvious ill-effects – raising hopes that a pesticide-free and entirely natural solution to one of horticulture’s most perplexing problems may have finally been found.

Al Reeve, SISI project officer based at Deveron, Bogie and Isla Rivers Charitable Trust in Huntly, Aberdeenshire, said the idea to introduce sheep to tackle the problem had originated almost by chance, but had proved surprisingly successful.

He said: “We were casting around for a way to get on top of the giant hogweed problem and came across a book that mentioned sheep had been successful somewhere in Europe, but it was anecdotal and there was no further information. It was a last roll of the dice.

“We thought we could chuck sheep at the problem and see what happens. As it turned out, they selectively opted for the hogweed over grass and turned out to be very effective.”

Initial concerns over the impact of giant hogweed’s high levels of furanocoumarins – the chemical which makes the skin sensitive to light, resulting in burning – on the sheep were quickly shown to be unnecessary.

He added: “We initially used black faced sheep thinking the pigment in the skin meant they’d be less likely to be affected, and then switched to Aberdeenshire sheep. They didn’t get burned either.

“We are using male sheep which have limited value to farmers – they are like four-legged lawnmowers. We have also seen evidence of stems chewed probably by deer and observed cows eating it too. Our hope is that we can demonstrate that it’s a much more efficient and cheaper way to treat hogweed.”

Giant hogweed arrived in Britain in the early 19th century as the nation became gripped by the discovery of new plants from exotic climes.

It is first documented in the Royal Botanic Gardens Kew Seed List of 1817, which notes it as being supplied to Kew by the Russian Gorenki Botanic Gardens.

The plant’s huge scale – it reaches heights of up to three metres – captured the imagination of gardeners seeking the latest exotic species for their gardens, and giant hogweed was soon widely planted in ornamental gardens.

However, its seeds spread rapidly and a decade after arriving in the country they had already established in the wild.

The plant’s scale means it throws shade over native vegetation and inhabits growth of other plants, while the risk of injury makes dense colonies tricky to remove by hand.

As a result landowners are faced with having to draft in trained staff to use chemical sprays.

As well as tackling Giant hogweed, the SISI is also seeking solutions to other weeds commonly found along river banks, including Japanese knotweed and Himalayan balsam.

Another problem plant is American skunk cabbage, a yellow flowering plant on sale as recently as 2009 and which is now spreading into the wild, smothering native flora including vascular plants and mosses.

The giant hogweed study is not the first time sheep have been deployed in the battle to solve a range of horticulture issues.

Wool from rare Whiteface Dartmoor sheep has been used by one innovative producer to create sustainable garden twine to replace imported jute. The wool twine is said to outlast the jute version.

Wool is also a key component of certain chemical-free slug pellets which, when moistened, swell and release tiny wood fibres that create a barrier which repels pests like slugs and snails.

Sheep’s wool and sustainably-sourced bracken has also been used to create peat-free compost.

While the woodland area chosen for the latest trials will be fenced, Mr Reeve urged dog walkers to take care near the trial area. “We know that this is a popular path for dog walkers. We ask that people remember there are now sheep in this woodland and act accordingly.”