Help identifying this woodland weed

[Swamp_Fox]

This year will be the third year that I have been dealing with what I believe to be Japanese Knotweed. Thus far I have been cutting it in to August and then spraying it in early September. This weed is relentless, always coming back and always spreading. I'm getting ready to apply my war paint for the year and have at it again, but would love to hear if it is infact Japanese Knotweed. I know it exists in Wisconsin but I have never seen it anywhere before or since discovering it on my property.

What I know about it thus far is that:
It's hollow stemmed
Fast growing
And very aggressively spreading
It has not had any success in my lawn
Has been popping up all over areas of non maintained parts of my property.
If it is only spreading via stolons it is capable of spreading around 50 feet or so from other plants

Thanks for the help!

[Swamp_Fox]

Some more photos.

[Dom_P]

That doesn't look like Japanese Knotweed to me, but can't say for sure. Mine starts off as small stalks that look like reddish asparagus. Then leaves start to form. In a week it's about 6in tall and will grow to 6 or 7 feet if left to its devices. Mature plants have very woody rhizomes that will travel for many feet. I have pulled some out that are a couple inches in diameter. In the winter it dies off and leaves what looks like old bamboo shoots. They are woody and hollow like bamboo. But very brittle.

I thought it used to look ok in the wooded part of my backyard until it started to invade my lawn. To keep it at bay I spray it with glyphosate and mow it down in my lawn. It will weaken but it's a yearly battle.

[TimmyG]

Definitely not knotweed. Looks a whole lot more like pokeweed, which should be downright obvious if it produces the telltale dark purple berries in the fall. I eradicated a vast colony of pokeweed in my woods after moving here in fall 2014. I believe I used more triclopyr than glyphosate.

viewtopic.php?f=4&t=17370

[Swamp_Fox]

TimmyG,
Thank you for your recommendation! I looked up Pokeweed and it certainly does look very similar, though I've never seen berries on mine. I do try and trim it back pretty regularly, I've only let it go to grab pictures of the plant. I'll take your info to the farm store and see if we can pin it down to pokeweed for sure. What methods have you used to control your stands of this weed?

[TimmyG]

What methods have you used to control your stands of this weed?

I believe I used more triclopyr than glyphosate.

Whether or not that is exactly true, you should have no trouble killing it with glyphosate. Google "pokeweed control", and you will find hit after hit after hit pointing you to glyphosate. In the fall of 2014, upon moving here, I sprayed mature plants loaded with berries. In the spring of 2015, I sprayed often, never letting any plants get much taller than, say, a foot. I was poke-free by fall of 2015.

[Swamp_Fox]

Aw man. I'm sorry I missed your previous post TimmyG, I tweaked my back really badly the other day and haven't been sleeping so well since. Roundup is is! Thank you for your help TimmyG!

[rydaddy]

Sorry, I'm late to the party on this one. Dealt with (what seemed like) a 'pokeweed' farm a couple years ago. 3 rounds of glyphosate with a week between worked for me. Mine were 4' tall before I started to deal with it. Don't forget surfactant.

[TimmyG]

Good luck, Swamp_Fox. Honestly, I don't remember pokeweed being all that difficult to control. It's just that it's both a persistent perennial and a prolific seeder, so it took a number of spring application outings to get the various stages of growth. Don't use glyphosate with diquat; you want the slow thorough kill of straight glyphosate, particularly for the old growth.

[Swamp_Fox]

Thank you for the tip Rydaddy and TimmyG. I'm confident I'll get this licked. I've got plenty of Garlon and Roundup laying around and gallons of surfactant . Perhaps I'll try a stem injector on a stand for fun, I'd but curious what effect I'd achieve injecting Imazapyr.

[JoyceMaddox]

Agree with you, TimmyG.