Japanese Knotweed 😩

Awful stuff and make sure your well covered up. Knotweed seems to be very resilient against most weed Killers but I've heard Grazon90 pretty tough.

I've not come across much of this weed here in the Midlands but I was in rural maryland, USA for a few years, it seems there approach was spraying but afterward they dug up roots.

Good luck, just be careful, I believe it can give a nasty rash 😉

I injected Roundup Biactive into the stems 3 years ago. Small bits of regrowth since only. Will struggle to control it here though as I have it on the riverbank and it keeps getting washed down to me

I've being spraying 2 spots on the farm for about 5-6 years now. Father at the time didn't know what it was until I told him. When I started I had to be lifted using the tractor loader to spray it it was that high. Thankfully it's only small shoots in the 2 spots which I spray each summer & Autumn. It never spread any further or massive growth since

Spotted the JKW on a small patch at the far corner of our farm 4/5 years ago. It must have been 8 foot high at least and covering 20 square metres. Roughly 100 or so shoots coming up from the ground. The first year we sprayed Roundup early in the year in April to reduce the growth throughout the growing year and then sprayed in mid-September to get it into the roots for Winter. There was probably 3/4 the amount of shoots the following year.

Each year since we've used Forefront T (using same application method as Roundup) and finally this year we're down to 1 shoot. We switched to Forefront T as it doesn't kill the grass around the area, so less bare ground for new shoots etc. It uses two chemicals (aminopyralid and triclopyr) instead of Roundups one (glyphosate).

Also, I see a suggestion above to cut back the plant, would heavily advise against this as even the tiniest of fragments from the plant can cause new growth. The local council decided using a hedge cutter on a local road with some JKW was the best course of action and now there's a good 1 mile stretch of JKW that's now sprayed every September instead.

Definitely do not cut it. Can you spray in situ and then burn (ie petrol) the dead stalks and stems as they stand.

Avoid moving it or other material close by. Avoid grazing nearby if you can.

Best of luck with it

Hedge cutter went at one stand near here a few years ago, the whole length of the cutting that day has it in groups now.

To try something new, I bundeled up a small patch of JNW into zip lock bags this month. It takes a bit of time to do this, espically if you do not want to break any of the stems/leaves, but the JKW was amongst some plants I did not want to harm.

Filled about a dozen bags before pouring in some glyphosate. Most of the bags have gone full brown now, so presuming roots too, will top up any of the bags that didn't brown fully again.

Haven't heard of this approach, time wil tell.

A bit of reading on the subject

Roundup,ll kill it, just watch out, the rhizomes could burs into life several years after you reckon you’ve the hoor killed. It can be done though…I sprayed it in may and sept, and really wet the earth at the base

Please do noy cut it. You will be aiding the spread.