Answer: Poison ivy is a very persistent plant and will take some time and effort to eradicate no matter which method you use. The safest way for neighboring plants is to smother it by cutting it off at the ground, then covering it with a heavy layer of newspaper or cardboard topped with a thick layer of mulch. Repeat as needed.
A faster way is to use the herbicide glyphosate according to the label instructions. Be aware that this is a nonselective herbicide and can kill neighboring plants. Sometimes, it is possible to shield the desirable plants with cardboard or other material until the herbicide is dry. In tight situations you may find it easier to wipe it on than to try to control a spray, too. Note too that it takes quite some time for the herbicide to translocate to the roots, so be sure to read the instructions.
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