A tarp will not kill the poison ivy if it is just there for the time, I assume weeks at most, that it will take you to cut the vines from the tree. I'd think you could just cut the vines at the base of the tree in a few minutes, and let the plants wilt in place and die in the tree. If you had access to a sickle mower, you could mow a path to the tree, thereby cutting the poison ivy. You could choose to apply roundup to any cut surfaces you saw in the poison ivy, do your cutting at the tree and leave. It takes a while for ivy and creeper to get badly wrapped in a tree; my guess is that if you cut leading bases of the plants once a year, you will do a lot of good. Note also that you can buy cheap tyvek pants and jackets to wear while working in the ivy. Wear washable shoes, hand protection, and just wade into the mess. Renais

Usually simply repeated knocking the Aphids off a plant will eventually reduce the population, if done relatively often. Understanding a bit about how Aphids live can also help control them and mostly they are attracted to the lushest, greenest growth, that with high Nitrogen levels. Aphids give birth to live young, almost as soon as they are born, so if you knock a bunch off with a sharp stream of water and in a couple of days see more Aphids you are not seeing those you knocked off but another generation. Aphids have a life span of about 30 days, total, so those that get knocked off the plants will die before they figure out where they came from and how to get back there. An insecticidal soap should also work as well as the sharp spray of water, but no better, if real soap is used and the mix is 1 teaspoon of soap in 1 quart of water, about a 1 percent solution. More does nothing except waste your money and detergents do not work.

nywoodsman's worldview is such because he has never experienced poison ivy like the rest of us! My wife and I are very allergic to p.I. But she is more allergic than I. We went to Disney World one year and they wouldn't let us in to a tour group because they thought she had a highly contagious skin disease (like eczema) on her face!! We had an abundance of it growing in a shrub we wanted to keep. I trimmed the shrub but avoided p.I. like the plague!! But it got so bad growing out of control each year that this year I had to do something. I obtained SYRVET's OB Veterinary Gloves which go all the way up to the shoulders (you can get them on Amazon). I had my wife tape them to my shoulders--however, you have to tape them across the back of the shirt, from top of glove to top of glove because the sweat will cause the tape to come loose and the glove will descend down to near the wrists. Not good!! After I finished working, I had my wife carefully pull the long gloves inside-out and we placed them in a plastic bag for disposal. She had to wash right away but did not get any rash. Once the gloves were off and disposed of, I immediately used Technu on my hands and wrists by rubbing them for several minutes. Then I used a liquid soap on that and washed my hands and wrists off. I followed that with a shower. Don't think that wearing an old pair of pants will protect you completely! Some of the urushiol oil penetrated the cloth and I got a rash on my thigh. I treated it with Technu soap regularly for several days. That did not get rid of the rash but it did lessen the severity of the itch. Some may be interested In knowing that Technu also makes something called "Tecnu Corticool" which is a hydrocortisone that gives you relief from the itch. But you will have to apply it again after awhile. This cream comes in a 1.5 oz tube and can also be gotten on Amazon. Hope this helps

Legal recourse usually means you have to demonstrate financial loss of some kind. For a hobbyist home gardener, that's not easily done. If the poison affected people or animals, there would be a case. But most common herbicides are considered safe for people at normal exposures. For damage to plants, there's very little that can be done. If she used a landscaping company, I might be able to seek recourse that way, but private use of herbicide on personal property? Her "gardener" is just a guy she grossly underpays to do yard work. He's a nice guy who works like 3 jobs just to feed his family. I'm really not interested in action that could have negative consequences for him. If anyone knows of cases that have actually gotten some kind of recourse, I'd love to hear about it.