Hi - we managed to get rid of knotweed completely - will tell you how I did it. I'm here because of a BBC article and got me remembering and thinking. I don't understand why everyone says this is so difficult to get rid of it seemed really easy to me anyway. 4 years ago we bought a flat - it had knotweed noted on the survey, it was pretty big area of huge tall weeds, but we haggled the price and bought for cash. Told we wouldn't get a mortgage because of the knotweed. Neighbours told us it was a nightmare they had battled for years and told us all the stories of council officials coming out to look at it and trying to apply for grant funding etc etc to get it dug out with JCB's and burned. Anyway, we decided ourselves to get an estimate from a professional company - priced in the £000's. I did some reading and research about the plant and controlling it. Went to b and q and bought a large quantity of the strongest glyphosate I could find, it said it could treat like 500m/sq. this patch was maybe 20 metres by 5 metres - pretty big for me anyway. It was supposed to be pretty diluted but I only used about 10% water maybe. I also bought a £15 manual spray pump and some gloves and some sponges. I went with some ladders on a Saturday morning in August, it was about 15 degrees C, cloud cover and dry. i coated every single leaf I could with the stuff - several times during the day and again after it dried off or was absorbed. I then found all the thickest stems and bunches and cut them down about halfway, and poured the stuff into the stems - filled right to the top. Then topped them off later that evening - and used the last of the strong spray solution I had made for another final spray coating. Over the next few weeks they starting visibly dying. The winter came and went and by July the following year everything was completely dead. I took plenty of before, during and after photos which I still have. That was 4 years ago I did that and not one single sign of it has returned. It cost me like £80 of materials and maybe 12 hours of my time. I knew nothing whatsoever about Japanese knotweed or plants and gardening and still don't. I was later told that national rail and the local council had actually sent 'a man' every season for 'several years' previous to our buying the place to 'spray the plants' to try and get rid of them. With little success apparently. What I find totally and utterly bizarre is that someone like me, completely clueless about horticulture and plants, was able to completely kill - permanently - a pretty substantial bank of this stuff in like 1 day, with stuff bought from the local hardware shop - and yet the Internet is full of stories and news reports of people spending fortunes and despairing in heartache over it. Was I lucky somehow? Genuinely I've always been curious about this and would welcome input from those more experienced.

Looks like Japanese Knotweed. From the descriptions I have read on the web, it is indeed hard to get rid of once established. Digging up and burning the plant, stems, roots and all is the best course of action. So jump on it right away!

JW has large, unlobed, heart-shaped leaves and hollow cane-like stems And does produce an aggressively creeping rootstock instead of a tight clump of growth. As an aside the common nuisance kind in some areas - including much of the Pacific Northwest and Great Britain - is Bohemian knot-weed rather than Japanese. It is an intermediate hybrid resulting from the crossing of Japanese and giant knot-weeds, with the hybrid plants often being male. So that there is not a problem with these male plants reseeding. Just covering large spaces with their vegetative growth if they are not destroyed. I have seen uncontrolled patches in my area occupying square footage the size of entire building lots - and bigger. If still nobody has done anything about it there is an infested bottom-land in the bend of a river in a National Forest east of here that may be something on the order of an acre in extent.

Neither photo is Japanese knotweed. But the first IS a knotweed (aka smartweed, jumpweed) and looks like Persicaria virginiana.