Keep after it with the round up.
I know a consummate gardener who has a bed of that around a tree...it's been there for years and never travels and looks great. I asked her how she does that and she says the regular lawn broadleaf weed killer takes care of the creepy crawley bits that escape.
Keep hitting it with the round up...
Awful stuff!! Almost as bad an gooseneck loose strife!!
Linda C

OK, thank you. I was worried that even the Roundup might not kill it, but I'll just keep after it.

Sometimes I get very annoyed at the nursery people who assure me that something is not invasive. I should have known better on this one.

Thanks again.

I would suggest that you either live with the plant (I do have it in an area where it's attractive and competes happily with maples, elm tree roots, woodruff, mint, hostas, lilies, daffodils and species geraniums) or resort to tactical nukes. At one point I tried to get rid of the mint. No go. Then I tried to get rid of the woodruff. Double no go. THEN I realized how rampant the bishop's weed was. Too late. Triple no go.

I have found a good way to cut down on the mint-drink lots of mojitos! Too bad this won't help with your bishop's weed, though.
Jen

I wouldn't use herbicide near a tree-

Trees do have lots of reserve strength, but I'd be afraid that eventually the poison would kill them.

To keep roots from snapping off, you can loosen the soil first with a garden fork or a spade & then work the roots out.

Best luck!

I got rid of mine - it took a few years to eradicate it entirely, but eventually, it was all gone (having said that, I'll probably get home tonight and find some lingering in some part of the back corner of the yard!).

Best thing (for the environment, certainly, but also to protect your other plantings, including your trees) is to pull or dig it out. Water the area really well the day before you weed, to soften the soil (which will help you get down to the roots without breaking it off at ground level). You won't get it all, even when it looks like you did - there will be fragments of roots that won't wait long to put out new growth. Be persistent! When you see some coming back, dig it out - again, and again, and again. And whatever you do, don't ever let any of it go to flower! You will win this battle, but you can't give up!

Good Luck...this plant is very pretty, I can see how you might have been tempted at the garden center, but it's a wolf in sheeps clothing!

Does anyone else INJECT Round-Up?

I've found it useful for poison ivy that is interwoven in our hedges. I get a cattle syringe and needle (I got mine at Tractor Supply) and I fill it with Round-Up and I inject a little bit directly into the stem. Poison Ivy in particular has that "woody" stem, and this way I'm assured that I actually got some of the "tactical nukes" (LOL -- love that term!) inside the plant so that it can carry the "radiation" back to the "mother ship" (roots).

I haven't done a complete inspection yet, but so far I haven't noticed any new PI this year in the areas I treated last year.

If anyone else is going to try this, use a SENSITIVE hand at this -- if you try to inject a whole bunch into a stem, the excess will either squirt out where you're injecting it in (all over you PLUS the plants that you're trying NOT to hit) or else the stem will burst under the pressure and the excess will spray out at random (all over you PLUS the plants that you're trying NOT to hit).

Since you're putting this directly into the plant's "veins", it really doesn't take very much at all. Think of how a single drop or bit of errant misting on a leaf can kill an entire plant and you get an idea of how very little of this stuff you have to get inside the stem in order for it to be effective.

Hockey? What dilution do you use? I'm trying to do that with bind weed, but the stems are so skinny....however I have an area of Virginia creeper. It really looks lovely way back under the trees and it does choke out the creeping charlie (Hee hee!)...so I have to decide if I really want it gone or just "under control"...and if I would rather Virginia creeper or bind weed!
Sylvia, Round up is perfectly safe to use near trees and even on the old wood bark of a mature tree, it's also, apparantly, safe to use directly on the leaves of Virginia creeper....won't hurt it a bit!!
Linda C

lindac --

I *think* that last season I had a bottle of Ortho's Brush B Gone concentrate at the beginning of the season and regular old Round-Up concentrate towards the end of the season.

In both cases, I did a rough-estimate when mixing it up and I tend to err on the "more is better" side for things like that. When only mixing up a Dixie cup's worth to use with my syringe, I just can't bring myself to convert all the volumes to reduce to formula, blah blah blah. I splash some chemicals in the cup and then I fill it with water from the spigot and call it good enough.

FWIW, I used the "injectocide" method on my Virginia Creeper as well -- didn't get it all, but did cut it WAY back from where it was last year. (I think that I missed quite a bit of it -- it's growing in a not very accessible area of our yard, between two fences with no direct access, so I only got the vines I could reach, unlike the poison ivy, where I had access to each and every one of the little boogers.)

Oh, and Round-Up WILL kill off lilacs pretty well....hubby went a little crazy with the Round-Up one day. :o(