It's War in the Garden
Lorna Blackwood seeks help in her fight against Japanese Knotweed
When I bought my flat with a garden, I had visions of warm summer evenings and weekends spent in my perfect oasis of greenery. Unfortunately, this tranquil dream has yet to become a reality - and it is nothing to do with the erratic British weather. Something much more sinister is to blame: Fallopia japonica, more commonly known as Japanese knotweed.
For those not familiar with the plant, I congratulate you on your luck. But those unlucky souls who have encountered this triffid-like weed, I can only sympathise.
Japanese knotweed was introduced from Japan in 1825 as an ornamental plant. However, it soon proved itself to be a highly invasive weed which can grow to 7ft in one season, spreads relentlessly, damages property and overwhelms other garden plants. It is now classed as “controlled waste” under the Environmental Protection Act 1990 and requires disposal at licensed landfill sites. It should never be included in normal household waste and is listed under Schedule 9 of the Wildlife and Countryside Act 1981, making it an offence to cause or allow the plant to spread in the wild. Once I had discovered the perils of the plant, I realised that it was more common than I first thought.
The amateur
A fellow sufferer among my colleagues, Mike Krage, a designer, was introduced to Japanese knotweed at a young age. “I have memories all through my childhood of hacking back the stuff and burning it in the back garden. The only time it was any use was Guy Fawkes night. In the autumn, the plant dries up and is hollow so is great for burning on the bonfire.
But 30 years on, the battle still rages. “Last year, I was helping my dad clear his garden. I decided to tackle the clump of knotweed. As the ground was wet, I was able to pull out a couple of the weeds. I really felt a sense of achievement. But I failed to get the whole root out so I know that when I go there it will be back to its former glory. There are chemical solutions but I'm just not sure if I want to go down that route just yet.”
The professional
When I rang Richard Hill, of Lush Garden Design, for his expert advice, I was met with a long, loud laugh.
“Oh dear. It is a really difficult plant to control. It is particularly common in the South, where weather conditions are perfect: wet and warm. Cutting it down does nothing. In fact you are making it worse as the plant puts all its energy in the roots. Its favourite place is at the bottom of brick walls or on fence lines. If it finds a hard surface it will just run along it. I have seen people deck over knotweed only to see it break through, bending the wood.
“There are poisons that can be used, but I am not convinced these work as it is a very, very hardy plant. The only sure-fire way to get rid of it is digging it out. The best way of doing this is to employ some muscles. Contact your local landscaping company or even building contractor - it is akin to building foundations for a house as you have to go down a few metres to dig out the root.
“If you decide to dig it out, make sure you follow the root and you've got rid of it completely. To clear a square metre will take up to two hours. It is best to remove in late autumn or early winter when the plant has dried out and easier to pull from the ground.”
I am keen to keep my actions as green as possible and asked if there was a chance that my garden could become the beautiful oasis I dream about, without sacrificing my environmental credentials? Another burst of laughter: “Even if you managed to destroy the weed on your patch, there is the neighbours' share to contend with. The only way to keep it away would be to pour a thick concrete slab over the whole garden. In other words, an environmental disaster.”
The Times 6th June 2008
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