After you cut it and sprayed what was on the ground with Roundup, did the part that was rooted in the ground die?

For tough to kill weeds, I've found that undiluted Roundup works. I'd put plastic trash bags around the tree trunk to protect the tree and spray the PI with undiluted RU that has spreader sticker in it. After the RU is dry, take the plastic off the tree trunk. The RU should spread through the plant and kill the roots.

Do this on a day with no wind (and wear latex gloves) because the RU will definitely kill whatever it comes into contact with.

You could also try mixing RU and brush killer together, again protecting the tree trunk.

Good luck!

Deanna

Yes, roundup kills the stuff at the bottom. That's not my problem. It's the vines in the tree that are still alive. What do I do about them?

thanks!

Are you sure you cut all of the stems leading into the top of the tree? Poison ivy is not parasitic so they should eventually wilt once the stems are cut. Only other thing I could think of is that the heartwood of the tree is badly rotted and the poison ivy has somehow rooted through an exposed area of the bark, although that seems unlikely. Make sure there isn't a vine coming from an adjacent tree that you might have missed.

Yes, it's supposed to die, but it's green and healthy and vigorous. Was wondering if anyone else experienced this.
thanks

I just cut down some PI that covered a large dead tree.

There are numerious stems from the ground. I had to cut the stems one by one. Then I spray the roundup at each stem. After two days or more, I checked to see if I missed any. There were two or three places where there appeared still fresh leaves. Then I cut and sparyed again on the remaining ones.

So far I think most are wilted and dead. I'll continue to check to see is any still remains. If indeed there is any feeder from the trunk of the dead tree, when I cut it and spray it, then it should die.

I have the exact same issue. A previous owner of my home cut through the very thick poison ivy vines with a chain saw and cut well into the locust tree as well. He poisoned the vines at ground level and they are dead - no new sprouts or leaves. There is no connection to the ground yet the PI is flourishing beyond the initial 10 feet. There are 7 to 9 PI branches that extent ~50+ feet into the tree each one the size of a large PI patch & dropping nasty seeds into the landscaping below. I can see that the PI vine looks dead for about 5 feet beyond the deep cut and then springs back to a healthy look higher in the tree indicating a parasitic relationship with the locust. There are throngs of dead PI sticks and brambles at tree trunk level which probably still contain urushiol preventing me from tilting a ladder against the tree to saw through the vine at a higher elevation. I'm stuck. My guess is that this was a 30- 40 year build-up of tree/vine. Anyone who has ideas would be much appreciated. My only recourse at this point is to call in a professional. Thought I was crazy until now since there is nothing else on the internet about this.

Try bleach water or chlorine water after you cut it

"Try bleach water or chlorine water after you cut it"

NO. It all likelihood you'll just temporarily injure it. Any concentration of bleach strong enough to actually kill it would produce a local environmental issue and be the "violation of federal law" you read about on product labels. Use an approved HERBICIDE. That's why they are called herbicides! Undiluted roundup with a bit of sticker, even plain dishwashing liquid, will work. Triclopyr will work too, if you have a hysterical fear of glyphosate.

The forum needs some moderation technology added to prevent old threads from being bumped with useless "information".

The report of a poison ivy living as a parasite off a locust seems ridiculous.

Obviously cut all vines as low as possible. Then you will need to spray and spray and spray and keep spraying (in order of effectiveness for me, I have tons on the ground and in trees) 1. Ortho brush killer. 2. Poison ivy specific sprays (ortho and bayer are the ones I've used, I get them in concentrate then make the stuff more than twice as strong as they say). 3. Ortho ground clear. 4. General weed killer concentrate made extra strong 4. Round up.

if it is infested, you can't kill it, just control it. But it can be controlled pretty well, it just ales time and money.

One tidbit to keep in mind-poison ivy is a native plant and as such, there are lepidopterous species (butterflies) that depend on its existence for their own.

Hey, I don't like the rash anymore than the next guy, but the seeming war to eradicate this plant strikes me as off-kilter. Then again, I'm Nature Boy.

You really don't need to "spray and spray and spray". I've killed many a PI vine with a single, correctly diluted application of either a selective or general herbicide. (which isn't very diluted, though if you're using a 61% commercial concentration of something like triclopyr ester, doesn't and shouldn't mean straight out of the bottle either) It's far easier to kill than say, Smilax.

" the roots are pretty established and will continue to send up new sprouts after a few applications of RU. Several are required"

Again, if I wasn't clear the first time, nope. I've coated 4" diamater vines with either 3 way amine, triclopyr ester with a bit of wax dissolved in it to make it thicker, or concentrated round up* with a surfactant..definitely all 3 at various times...and they died. On the first try. All the way. Didn't even spray the foliage because it was 15-20' up in the tree. The root hairs on the trunk seem to make it especially likely to take up herbicides. What a nice feature. Good riddance horrid vine!

It might not work with stuff Joe and Jane Q. Public can buy at their local HD & Lowes...and that's probably a good thing...but it can be done. And it can be done according to the label directions. Although no sensible person would mechanically frill poison ivy, in one case I had just cut it with a chain saw. Using a respirator and eye protection!

BTW in no case did I damage the attached tree.

* whenever I type round up, I mean generic glyphosate. I haven't bought a monsanto made version in roughly 10 years.

I only use generic glyphosphate mixed according to directions. that may be why it needs more than one application. It works fine for most small PI on first try.

right, the labels for consumer products do not discuss the use of concentrated formulas directly on trunks and stems, but the labels for most professional versions do...I should have clarified that because I wasn't trying to say your experience was invalid

My Mr. is very allergic to PI. Of course it grows everywhere on our property. Every year he battles with it. and it always comes back, sometimes in new places on the other side of the property...Yes, we have a very thick PI vine growing up a maple tree, it goes way, way up....He did sever it in several places even though it already looked dead. but you never know...."Leaves of three let it be".