I'm with Ken NC. I'm in SC and am "rehabilitating" 7.5 overgrown acres, on which every tree (and there are a lot) was poison ivy or oak (look different, but pack the same wallop - heck, I even had poison sumac - didn't know it, but sure found out). I cut the stuff off at ground level (industrial strength trimmer), as I did all vines (prickly, mostly). The next year, as the stuff sprouted - well below the level of leaves on any tree, I zapped anything within 2 feet of any tree with RoundUP, at twice the recommended strength (when I used the "weed" strength - the poison ivy and brush ignored it) via a back-pack mounted sprayer. I walked around the property a month later, with the same solution in the sprayer, and zapped anything still hanging around. Now kids can wander my property and climb any tree - no rashes to bother mom with. Yup, it's labor intensive, but I did not kill any natural tree or shrub I didn't want to, and with RoundUp, you do not have to worry about contaminating your water supply. If you've a lot of land, the least expensive RoundUp concentrate (the 50% stuff, not the 25% stuff they sell you at the same price at their Walmart outlet) is at SAMS, but Lowe's has a multigallon bottle of such for $150 if you have 10 plus acres and loads of poison stuff. Good luck, and wear gloves.