difficult location for poison ivy removal

Question: Found a small amount of poison ivy in a difficult location under a catalpa tree. 3 stems in same location, possibly connected. I tried digging and the first stem broke off. Second piece turned out to go underneath an above-ground tree root, could not be dug. Third piece is starting up tree trunk. Leaves and vine on tree are small, but vine is already in the fissures of the tree. I tried painting herbicide on leaves (Roundup) which seems to be turning the leaves brown. Not sure it is going down to the roots though. Anything else to try ?

responder: Erin Hill, PhD  Replied July 08, 2024, 1:36 PM EDT
response: I would recommend cutting the vines and applying the concentrated herbicide (either triclopyr or glyphosate) to the cut stem that heads down towards the root system. You can paint this on to minimize any movement in your landscape, just like you did with the leaves. This allows the herbicide to be translocated into the root system for a more complete kill. Depending on the infestation level this may need to be repeated, but you should wait at least a month to see if anything resprouts before doing so. Every thing above the cut will die back over time.  Note, the irritating substance, urishiol, found on poison ivy remains even after the plant is dead and therefore it should be handled and disposed of with care. Poison ivy should never be burned to avoid the risk of inhalation.  We have a bulletin on Poison Ivy with management information at the end, which you may also find helpful. Link: https://www.canr.msu.edu/pestid/resources/plant-and-weed-identification/PoisonIvy_E3438_AA%20(002).pdf   Please let me know if you have any questions.

responder: The Question Asker Replied July 08, 2024, 5:45 PM EDT
response: Thanks for your response.  I had thought about cutting the stem but the diameter is quite small, about 1/8 inch, and I wasn't sure how to dab the cut without also getting herbicide on the tree. For such a small amount it probably doesn't matter though. For disinfecting my pruners I normally use alcohol; will that do it for poison ivy as well?    I don't like the idea of the dead leaves disintegrating into the soil over time so I will try to remove those now, before it rains. That site is now in my head as potential p.i. site, so I will be keeping watch for new growth. Unfortunately some good native plants are intermingled.    I appreciate the help. I followed the link you gave which was no longer working, but I was able to do a search on the site for poison ivy management. If I have any other questions I will ask.  Thanks again, Rachel        On Monday, July 8, 2024 at 01:36:13 PM EDT, Ask Extension <<personal data hidden>> wrote:

responder: Erin Hill, PhD  Replied July 09, 2024, 9:29 AM EDT
response: You could use a small paint brush or cotton swap (e.g. Q-tip) to dab the herbicide on the small stem(s).  Yes, you can use alcohol to remove urishiol, but you also want to rinse them with water afterwards. Soapy water can also be used followed by a rinse.  I'm sorry the link didn't work, seems like maybe it's too long for this program. You can download the bulleting at this link if you scroll down to the "download" button. https://www.canr.msu.edu/news/new-free-poison-ivy-bulletin-available-for-id-control-and-more  I'll leave you with one last interesting fact for now...poison ivy is also a native species in Michigan....but that doesn't mean it is desirable :) Hopefully the other species emerging will create a competitive environment to keep the poison ivy at bay. Returning to the area to scout for reemergence is a great idea!  If you ever have more questions and can't find this thread, feel free to contact me directly at <personal data hidden>

responder: The Question Asker Replied July 09, 2024, 11:49 AM EDT
response: Thanks Erin!  I like the idea of using a cotton swab. I had gone ahead and painted the cut stems with a paintbrush that could have been smaller. A swab would better soak up the herbicide and target the stems. After the rain we are expected to get I will recut some of those stems.    I had a woody plants class in grad school and poison ivy was pointed out as a native, and that it could be found in unexpected places. A tree invested with p.i showed up in one of our weekly field i.d. quizes.   I'm lucky to have had only a couple of minor direct contacts with this plant, and have become pretty good at spotting it. Usually I've been able to dig it out and carefully transfer to a plastic bag that gets knotted up and thrown in a sturdy contractor trash bag. You can't be too cautious with this pest!  Your advice has been very helpful. Rachel          On Tuesday, July 9, 2024 at 09:29:59 AM EDT, Ask Extension <<personal data hidden>> wrote: