The big war against weeds is in full Bloom
This weekend's Bloom festival has a garden dedicated to invasive species, writes Paul Melia
The wreckage of an alien spaceship lies in a corner of Dublin's Phoenix Park, but it's not little green men emerging from the fallen craft, but visitors of a different kind.
Himalayan balsam, Japanese knotweed and a host of other unwanted visitors spill out, intent on clogging up our waterways, eradicating our native plants and competing with wildlife for food.
But garden designer Fiann O'Nuallain, who created the 'Destination Bloom' garden that will be unveiled at this weekend's Bloom Festival, says it's time we turned the tables on these invaders.
"Why not harvest these pests and sell them, using the money to fund eradication programmes," he says.
Hundreds of invasive species ranging from plants to deer, mink and zebra mussels cost the economy more than €202m a year, a report for the National Parks and Wildlife Service says.
Many were introduced by the Victorians, while some arrived on ships or were deliberately released, and the State spends millions every year trying to eradicate them.
O'Nuallain, says there is another way of tackling the problem.
"Japanese Knotweed causes huge problems," he said.
"It doesn't spread by seed, but by its root system. It can cut through concrete, and many UK banks won't fund a mortgage if you have it.
"But it's a delicacy in Korea and China, and is drunk in the form of Itadori tea in Japan. It's also eaten as a steamed vegetable, like asparagus.
"We could create an economy for this."
It's not just knotweed that's a problem – rhododendron, which has beautiful purple flowers, carries a virus that kills oak trees and prevents native plants from growing.
In Indonesia, it's used to poison rodents, which cause about €5m worth of damage here a year.
Himalayan balsam clogs up our waterways, but the seeds are edible.
You can make glue from Spanish bluebells while the Cape Fig, found on Howth Head and along the east coast, is made into jam in South Africa. But there's potential to fund pest control from animals and marine life too.
The Chinese mitten crab, found in Waterford, burrows into banks, causing erosion, and is considered a delicacy in the Far East. The idea has taken off in the UK. Three years ago, a zoologist working in fisheries management was selling up to 20,000 of the environmentally-damaging American crayfish a week to chefs.
Some are even eating Grey squirrels – said to taste sweet, like a cross between lamb and duck.
The idea of turning these pests into foodstuffs has also been tried in "The Bionic Control of Invasive Plant Species" project at Wiesbaden in Germany.
The idea was to establish nature conservation "with fork and knife", and dandelion and nettle jam, a jelly from Himalayan balsam and a bread spread of Japanese knotweed was produced, with the proceeds helping to fund eradication measures.
It's a thing we could become very used to – you can already get nettle pesto in food markets, and one Wicklow game supplier says the Irish palate is prepared to try new things.
Michael Healy, owner of Wild Irish Game Ltd, stocks rabbit and red-legged partridge, which is considered to pose some risk to native species, along with ostrich, antelope and kangaroo for those with more exotic tastes.
"Wild game in general has had a good uptake over the last couple of years.
"When we started in this business nearly 20 years ago, there was a big thing about people not eating rabbit because of myxomatosis," he said.
"Wild rabbit is popular again, but they're not as plentiful as they used to be.
"People have become a lot more adventurous, particularly through education, and they will try new things. During the good times, when people had a few bob to spare, they were definitely being a lot more adventurous, and a big part of that was due to cookery programmes.
"But the marketing could be improved. The supermarkets don't seem to be pushing that line of product, because it's probably not a big enough seller for them."
But Fiann O'Nuallain says it's about people being willing to do their bit.
"In these recessionary times, people can play a part and government money could go to hospitals or infrastructure – it's just about changing the mindset of how we tackle it.
"It doesn't have to be government policy to attack Himalayan balsam. If we could market rhododendron oil or the dyes of giant rhubarb, it would pay to harvest it out of existence."