Do you know anyone who has had a ‘run-in’ with Knotweed? If you do you may appreciate what a nightmare it is. If you’re a home owner and either you have Knotweed in your garden or, worse still, your neighbours have it, you have a problem. It’s highly invasive. It can structurally damage your house, garage or driveway. Worst of all, it can make your property unsaleable.

Fallopia Japonica (Japanese Knotweed) is actually rather an attractive herbaceous perennial, so much so that it was imported into this country for its looks, first appearing in the Royal Botanic Gardens in Kew in 1850. It has a bamboo-like appearance, grows around 8cm a day in summer, and produces nectar that bees adore, and which bee-keepers can generate valuable monofloral honey where there’s an abundance of Knotweed. In the Far East the young shoots are regarded as a wild edible vegetable (sansai), which tastes a little like sour rhubarb. So much for the benefits.

The downside is that with rapid growth and shoots stronger than bamboo, a prolific crop can lift concrete driveways, burrow through brick and literally undermine foundations, causing subsidence. It’s very hard to eradicate, as the roots penetrate over a meter below ground, and when attacked can lie dormant for years. Known for its destructive capabilities, banks and building societies won’t lend on properties which has Knotweed in the garden or on properties where it’s within neighbouring gardens in close proximity to the property being sold.

We’ve come across it a couple of times in Meanwood, thankfully on Council-owned land. The Council responded rapidly to our calls and treatment programmes were implemented. Initial sales fell through, but with a guarantee of on-going treatment by the Council subsequent sales have completed – with full declaration to all parties, of course.

The real problem is where Knotweed is on privately-owned, neighbouring, land where the neighbour refuses to eradicate it. To date, home owners have been under no obligation to remove or even treat Knotweeed. Their only obligation has been to prevent it spreading to neighbouring gardens. In Roundhay we’ve had sales fall through in a block of flats simply because Knotweed was in the neighbouring garden, over the fence, no more than 10m away.

This week two home-owners of adjoining bungalows won a court case against Network Rail for Knotweed on the railway embankment. Network Rail had been attempting to control the Knotweed, but occasionally stems had found their way into the neighbouring gardens.

Previous cases have resulted in the Courts enforcing the owner of the land upon which Knotweed is present to take action to control it. But in this ruling the Court of Appeal held that Network Rail should compensate the home-owners, not for physical damage caused but for negligence in the failure to control the plant. Sir Terence Etherton, Master of the Rolls, said it “… does not merely carry the risk of future physical damage to buildings, structures and installations on the land. Its presence imposes an immediate burden on landowners…” The two claimants were awarded £10,000 each in compensation, plus the actual costs of having to eradicate the Knotweed.

This case will open thousands of property owners up and down the country to claims. It will also cost the taxpayer millions of pounds as Network Rail has to deal with the Knotweed on its land. £15m was spent last year dealing with Knotweed. That sum is likely to grow exponentially following this ruling.