I'd stay away from chemicals. Why?
Herbicides are generally useless when dealing with those poison plants, the dead curled up remains of those dermatologically dangerous plants can still give you a nasty rash. All parts of those plants - roots, leaves, stalk and stems, dead or alive, contain the oil "Urushiol" that triggers the reaction...
You have to pull them out, below is a highly recommended and effective method of removing poison ivy:
Collect as many thick plastic shopping bags as you can.
A large dustbin (trashcan) or large "heavy gauge" rubbish (trash) bags.
Somebody to help you, get someone you don't mind who sees you naked (reason being is explained later).
Don't do this without a helper. The helper is your "non poison ivy" hands while you're handling the poison ivy with your "thick plastic bag covered" hands.
Protect your hands, face, and other exposed areas with "Ivy Block".
Go out when the ground is soaking wet or drench it yourself.
Put a thick plastic bag over each of your hands.
Locate where each vine enters the soil and pull (very) slowly with one of your bagged hands, the whole vine, root and all should come out easily.
If the vine does not come out easily, get your helper to soak the soil around the base of the vine with a garden hose.
Don't you, the puller, touch anything. Keep you hands inside the bags and don't touch anything with those bags except the vines you're trying to remove.
Now that the ground around the vine has been soaked even more, try pulling the vine again. Finger-crossed it should come out this time.
Fold the bag that's been covering your other hand over the pulled vine, and drop the poison ivy and both bags into the dustbin (trashcan).
- Never re-use any of your "hand bags", always start with a fresh, clean set every time.
If the vine breaks leaving the root in the soil, get your helper to put a marker in that location, then come back the following day with the strongest vinegar you can find to kill the root.
- Obviously if you use vinegar to kill the root, care needs to be taken that you don't kill any wanted plants within the surrounding area.
When you've finished pulling all the vines, get your helper to open all the doors for you.
Go straight to your washing machine, put all your clothes in and get your helper to run them through a cold water cycle.
Or if they're old cloths and you can afford to throw them away, do so. Bag them up immediately and put that bag with the poison ivy you've pulled.
Get in the shower, have your helper turn it on, then wash yourself well with cool water. No soap or washcloth. Water alone will remove the Urushiol oil, soap and cloth can spread it to other parts, more sensitive areas...
Credit, the above procedure comes via, "Poison Ivy Problems? Pulling is the way to go - dangerous chemical herbicides are NOT!"
Some additional reading, "Polish Off Your Poison Ivy Without Personal Peril - With These Seven Secrets of Successful PI Pullers!"
They are all very easy to identify - a local book store or the internet is your friend for identifying them. eg
Note: Poison Ivy's most recognizable 3-leafed plant is not the only form - it also takes the form of a vine or bush. The most commonly seen (for me) is the plant form though the vine is common around where I live as well.
Good luck.
