We bought a house with some very neglected acreage late last year, and poison ivy is all over many of our trees. The vines are roughly 6 inches in diameter at the base, and most are deeply embedded in the trees (not just the bark), to the point where it appears the trees have grown around the vine.
I've been cutting the vines off at the base and pulling them off the trees where I can (I'm not allergic), but many spread out once they get to roughly 25-30 feet high, and then follow smaller limbs of the trees. I'm not sure who started that rumor that poison ivy only gets 25 feet high, but ours is well over 45 feet high on several trees, so I guess we must have the record breaking vines. Anyway, it circles these smaller limbs and the trunk, so pulling it from ground level doesn't work. Unfortunately, climbing to remove it won't work either, because at that height, there aren't a lot of other branches to use for support when standing or sitting upright, and it's much too high for an extension ladder.
By the way, no suggestions to simply pull it off, PLEASE. LOL I had a very heavy rope doubled up and tied around part of this ivy about 35 feet up, and tied the other end to a tractor to pull it down. This stuff is so strong it was able to lift the rear wheels of the tractor off the ground without breaking. Remember it is circling the limbs. ;-)
I don't mind using poison, but I do NOT want to hurt the trees on which the ivy is growing. Most are in the 2-4 feet diameter and 65-85 feet high range.
Another problem I've run into is when using a wide crowbar to pry out the vines that aren't too deeply embedded, the vines just snap and let the crowbar pass through, while the rest of the vine stays embedded in the tree. :S Removing 3 inches at a time of a 100 foot long vine isn't too much fun. The ivy that breaks like that is only about 1 inch thick, by the way.
Does anyone know of a chemical or agent that will kill the vine and cause those dang hairy root things to wither or otherwise release their grip on the tree, without hurting the tree??? If I can't come up with anything better, I guess it means a week of using my gaffs to climb a dozen trees to 75 feet high to cut it all and pull it off by hand. Even that doesn't work 100% of the time, because it breaks sometimes where it is thin (less than an inch thick), and that almost always happens on branches that are too small to climb.
It seems like there should be a toxic mineral or poison that could be hammered in to the thick base that would carry the poison to the whole vine and make it dry up and release its little tentacles. :P
Anyone with any ideas, please whip them on me!!
Thanks a bunch,
P.S. This is what happens when you don't take care of your yard for 10-20 years!