Permaculture way to deal with Japanese knotweed?

Hi,

We have moved to a 10 acre site in the East of England and are confronted with a roughly 20 metre square area under some ash and willow that is covered in Japanese knotweed. The advice to deal with it seems to be to either dig out a massive amount of soil, put a membrane down a few feet below, and bring in fresh soil on top - or to use chemicals to get rid of it over time. Both of which might or might not work.
I am currently experimenting with putting our two kune kune pigs on there to see what they think of it but am wary it could make the problem worse.

Does anyone know of a good permie solution to this invasive problem? Any ideas much appreciated!

Many thanks indeed
Ben

We are at a PDC right now in Detroit and have been considering ways to manage the Japanese knotweed too. Some of the students found research that suggests that the accumulated toxins are in the roots and do not travel up the stem. So we took some machetes and a few folks and chopped em down. Laid right on site, chopped up into smallish pieces. We are sheet mulching it out and could further cover that with other organic matters and plant right into that. We could plant non-edible productive plants though I think edibles might be just fine.

Good luck!

My neighbour had a problem with it encroaching from adjacent woodland. When he put sheep in to graze they ate it all.

Eat it. We were able to dig it out,be consistent

We eat the small shoots in spring and then just keep cutting it down just before it flowers. Every time it grows back a little bit smaller and weaker. By the end of summer the shoots are smaller than a pencil in diameter. I wonder if you planted a fast growing cover crop like buckwheat, if you could out compete it enough to kill it off?
On the other hand, it does produce a lot of biomass that does seem to breakdown easily. Might be a good compost additive. AND drying the stalks would make some nice hollows for Mason Bees to live.

My friend in Pittsburgh had a big patch of Japanese knotweed that she got rid of by putting a large, clear plastic sheet over all summer. The sun basically cooks them dead!

Thanks everyone for the really useful replies. We have the pigs grazing there at the moment and they are interested in the smaller leaves but not the bigger stuff. I like the idea of picking it regularly to make it weaker and then gradually taking over with an aggressive ground cover. Will be giving it a try.

Really appreciate the help

Ben

What do you mean toxins?
 I hope it's not poisonous I eat it when I'm in the field!  

jesse tack wrote:We are at a PDC right now in Detroit and have been considering ways to manage the Japanese knotweed too. Some of the students found research that suggests that the accumulated toxins are in the roots and do not travel up the stem. So we took some machetes and a few folks and chopped em down. Laid right on site, chopped up into smallish pieces. We are sheet mulching it out and could further cover that with other organic matters and plant right into that. We could plant non-edible productive plants though I think edibles might be just fine.

Good luck!