Eradicating Japanese Knotweed is a long process. In my first post about killing knotweed, I listed the initial attack tactic: amp up the attitude, spray with glysophate, and wait for a couple of weeks. There’s no way that stopping there will get you anything other than stronger, angrier knotweed. Stick with it! Here’s what to do next:
- Cut it down. Fallopia japonica can (and does) regenerate from clippings, so put down a tarp and cut the stalks off about a foot from the ground. Gather EVERYTHING in the tarp and dry it out, then burn it. Do not compost it. Do not trash it. Do not leave any pieces behind. Do not fail to completely clean your shoes and tools before leaving the area. Destroy it.
- Spray it. What?? Yes, more Round-Up/glysophate. Once you cut it down, you’ll have the gaping maws of the sheared canes exposed. Stick the nozzle right down their throats and spray with abandon. Renew your commitment by imagining them gagging and choking.
- Wait. Give it another couple of weeks. Yes, this area looks like hell. War is hell and you are at war with this plant.
- Spray it! Really? Yes, because the thing will most likely put up some sprouts. Look yards away for sprouts – I found some that vined under the porch and came out where it thought it was safe. Coat the leaves on the new growth, top and bottom.
- Wait. A couple of weeks, yes. And while waiting, imagine the plant in its death throes. Hate it a lot! You have reason.
- Dig! Get your tarp out again, and start digging. The roots will be unbelievable – woody, thick, gnarled, vicious. You’ll need a saw. Dig. Cut. Dig. Cut. Tease out the smaller roots. Follow every big root you can find and get it out of there. Gather everything on the tarp; you’re going to burn it or encase it in nuclear waste. (Burning is more practical.) I also had a heap of dirt that I screened and supplemented with clean fill. When I was doing this, I had a trench over three feet deep. I insisted the Kev spend some time outside so the neighbors knew he was well. It looked as if we’d had some sort of extremely serious argument with illegal outcomes.
- Keep hating it!
Now, we’re getting somewhere!
Part of my cunning plan is to keep weakening the plant’s reserves by repeated trauma and cutting. If your diet is knotweed jelly-deficient and you are committed to hacking back the shoots religiously, this technique may work for you. But I hope it’s obvious that you should do one or the other! Any knotweed shoots on my property are brimming with poisonous goo, and not the yummy kind.
At this point, the Japanese Knotweed is definitely on the run. Tune in for the thrilling final episode…