That's fine if it does not destroy your garden.Before any more of the "Treat it with chemicals" brigade offer their myopic suggestions , leave it as it is.
It won't cost you a penny, it will provide a home for many thousands of insects, invertebrates, and small mammals, which in turn will provide food for many more animals further up the food chain. And the pollinators will take advantage of the available food supply, which in turn benefits the human race, because without pollinators we're basically stuffed.
Or you could spray it with chemicals and pretend that you're not damaging the planet...
I won't use anything with glyphosate, it devastates insect populations. Ammonium sulphamate all the way.
I would agree its not ideal but there are very few other options for commercial weed control. I would like to think most responsible sprayers are only spot spraying with it.
Bob
I've been killing Japanese Knotweed with Gallup 360 over the wall at the bottom of our garden for a few years now, got it back to about 20 feet away and the Blackberries and Teasels have taken over but I don't mind them so much. I tried just cutting the JK down but it was not working.
If I attacked the job again - from day one - I would have dug the stands out and burned them on site
You do know that the roots can go down 2 metres?
Thats the thing. any weed is easier to kill if you cut it down then treat the new growthI use a propane roofing felt torch to burn them to the ground and then apply weedkiller to the new growth