Japanese knotweed Camborne, Cornwall - TCM

Its tall, green and tough. It's not the Incredible Hulk, but Japanese knotweed is the nemesis of housebuilders everywhere.

Now one firm, Midas Homes, is spending over £2m on booting it off one of its sites.
Japanese knotweed
Credit: Dankogreen

The housebuilder, which is working with English Partnerships on a 390-home scheme in Camborne, Cornwall, is trying out a new technique for getting rid of the persistent plant. The soil containing the knotweed will be sorted by hand to remove the plants which will be incinerated. The labour-intensive treatment, carried out by TCM (Thurlow Countryside Management), will cost over £2m. It has been used once before on the Olympic park in east London.

Normally we would remove it from site or use a herbicide similar to Roundup you would use in the garden, says Glynnis Poole, Midas engineering manager, but herbicide had time constraints and waste disposal is very expensive and there are a very limited number of sites that can take knotweed material.

Previous applications of herbicide had not worked and it would take about three years to eradicate the plant using chemicals time the developer did not have. Removing the 70,000m2 of material to landfill would have cost about £5m.

The soil on the site included mining spoil. The man made soil was full of gaps allowing rhizomes of the plant stems which live underground and send out shoots and roots to travel underground and making it harder to kill with chemicals.


Cambourne

The man made soil needed to be dug out anyway, so the developers decided to have it treated manually after excavation and put back once it was clean. The cleaned soil will be put back in at a lower level at least 4m under the surface so any residual plant matter will be well buried.

At the moment things are on target both on time and budget, says Poole. The project should take six months to a year and began at the end of September.

For more information please email info@t-c-m.co.uk or telephone 01440 760170 www.t-c-m.co.uk

Category:

Science & Technology

Tags:

• thurlow countryside management
• midas homes
• knotweed removal
• camborne cornwall
• land remediation
• tcm .
• japanese knotweed

[randomdave30]

Get unemployed people on the dole to get off their backsides and remove the knotweed by hand

[hitachi088]

@icicicles i saw somewhere that it was .6 gram.

[icicicles]

It takes less then an inch of root left behind to begin growing again.

I doubt there getting them all out.

[margot980]

@bluenail90 The leaves, like rhubarb leaves, contain oxalic acid, which yes can cause all sorts of problems, including kidney stones. It is well known that eating rhubarb leaves is a bad idea.

Like rhubarb stems, knotweed stems, especially if eaten a few times in April every year, strike me as highly unlikely to cause health problems. Maybe watch out for the creamy gooey you dip it in as you sip your pilsner.

[bluenail90]

@margot980 long term it causes kidney stones.

[margot980]

When the stems are about knee to thigh high, pick juicy ones and cut into short sections, about three inches, or from knot to knot. Peel the lovely speckled skin off, dip in anything creamy, and nibble with a nice cold pilsner. An April treat without equal, especially on one of the first hot afternoons.

If developers don't care about mining waste, maybe knotweed is a great way to send them packing.

[MsFlyagaric]

This is an extremely interesting and informative video, and highlights this companys innovative approach to Japanese Knotweed Eradication.