Yesterday i went to cut some Japanese knotweed (JKW) and dug a bit deeper than i usually do.
I found this giant root that was tougher than the usual rhizomes, but much more brittle than a tree root (felt a bit like JKW). No trees in 10 meters distance.
What would you guys do about the root? Removing the entire thing will require an insane amount of work.
by nkkh93
37 Comments
Yikes. I would probably just try to exhaust it by continuously mowing or otherwise cutting that patch, assuming it’s entirely accessible on your own property.
Nice dirt by the way.
horrifying
I’ve heard success with covering the patch with hard-wire cloth that’s small enough to girdle the shoots as they grow through the wire.
could it be injected with something? painted with something? kill it all off?
I read the new shoots can be used pretty much like rhubarb
Yeah, that’s the main root. I’ve read they can go as deep as 6-feet, which is why the stuff is so difficult to eliminate.
Can I get a banana for scale? The shovel just isn’t doing it for me.
Check out r/invasivespecies for help
I’m also dealing with Japanese Knotweed invasion and boy is it a task. I think the previous owner of my house planted it on purpose! The advice for my area is not to cut it as this will encourage it grow underground and potentially pop up in other areas far away from its current spot. Instead, there are programs to spray or inject it with herbicide, but this has to be during a specific time of the year. For my area, this is September/October.
Good luck with getting rid of it! I think a lot of areas globally are dealing with the same issue, unfortunately :/
I have found massive rhizome like that as well. It was my first year spraying it with glyphosate after it flowered this past fall. I have a couple of shoots coming up this year but 90% less than last year. And I had quite the patch that consumed more and more of my yard each year. I plan to spray every fall until it’s fully gone. Thankful my neighbors also allowed me to spray their yards, so hopefully we can fully eradicate it.
You guys need to get over to r/invasivespecies. JKW has a very specific window to poison it. There is no other successful way to remove this species aside from digging and removing every single root.
Do not mow, do not partially dig. Poison it in the autumn each year untill it’s gone and then never dig in that space again. Lay down wildflower seeds or grass seed and then leave it alone
Don’t worry about the root. Leave it there, cover it back up. Wait for the shoots to appear then paint on Roundup. Repeat next year. If you have a large stand you might need to spray it in the autumn.
Don’t bother with laying mesh to girdle the plant. Yes the young shoots are edible (before herbicide application), but that won’t help eradicate it obviously. Don’t bother with cutting or mowing. Just glyphosate. Act now before it’s too late.
I think that’s actually one of the graboids from Tremors. 😂
This shit will take over all of north america
Japanese kNOTweed. Yup, not weed for sure.
Found JKW under my front garden shortly after moving into my first home last year. Everytime I dig to plant things it just…..appears. I always know it’s under there. Spreading. Watching. Waiting. Growing stronger everyday. And there’s not a god damn thing I can do about it.
Wow
What da root doin?
I would saw the root in half, cut a notch, and douse it with Tordon. I’ve not dealt with this species, but Tordon works great on the evasive ones I have.
Ffs, k..ll it off.
My neighbour decided to grow it in the ground on purpose. It’s starting to spread everywhere.
This is one of the small worms that comes out of the big worms mouth from tremors.
Damn!! But aside, wondering if this soil is clayey or considered sandy?
Physically ripping it up will not be effective. It can re-establish from tiny pieces as small as a finger nail. Physical removal will knock it back temporarily, but it’s incredibly resilient and will grow back and most likely expand its footprint.
Be very careful with any dirt or plant matter you have dug up or ripped out. JKW can very easily establish itself in a new area via “contaminated” soil. Any plant matter you have removed can be burned or placed in a thick trash bag and left in the sun for several weeks to decompose. Don’t dispose of it directly in the trash or move it to a new area.
The effective approach is to let it grow until early fall, then inject stems with glyphosate concentrate after the plants have flowered. This brings the herbicide into the root system and kills it at the source. This method is very effective, but takes a few years to eliminate a patch entirely.
Looks like the root I found for the Virginia creeper I’ve been trying to get rid of. I followed it all the way to what I suspect was the root ball and dug that bitch out. So far I haven’t noticed near as much popping up in my yard this year. There’s an enormous trench and hole under my kids’ play place thing though 😬
Was this spade made bespoke for Peter Crouch?!
DAMN!
This is honestly horrifying
Just to note, OP is in Denmark, so glyphosate may not be an option? OP may need to figure out local and national laws on use even for stem injection.
Cut it and stick both ends in herbicide
TREE STUMP KILLER
Around here this is an invasive species. You can’t root it out and even the tiniest clipping ( 4mm) can take root) root go very deep and destroy concrete bridges and it pushes out local plants. Make sure you clean your tools burn every minuscule piece of that plant or bury it were you found it
Japanese knot getting rid of me today weed
Step 5: nuke it from space
Get a pro and probably costly friendly invasive thorough contractor to get rid of the darned thing. It can grow through, I think, fifteen foot of concrete and if every single last bit of it isn’t eradicated it can grow back. It’s a nightmare and people can be sued if they sell a house and they fail to notify new owners there’s jkn on the property in parts of the UK.
I wonder whether sabotage is deliberately being done by bad actor gardening sorts planting this horrid plant all over the place. Barstools. It’s ruinous.
This does not answer your question, however the shoots are very edible raw. They taste kinda like rhubarb. You can cook pies with them also replacing rhubarb. Yum
Inject with with glyphosphate.
Fight final boss.
Have nice garden
Fire!