I have a problem with poison oak/ivy. I have a number of scrubs in my back yard. I have what appears to be poison oak/ivy (leaves of three) that shows up in various places. I have developed the rash on several occasions over the last ten years. I have been told that a product like Round-up will kill the plant down to the roots. Is this true? Do I need to find all the various plants or are all the plants from the same root system? Can you recommend a book or pamphlet that can help me with this? Thank you for your help.
It is very possible that you have more than one plant. Wearing gardening gloves, by pulling on a vine, you may be able to see where it is coming out of the ground. If so, you can cut it off near the ground and pull up the roots.
Glyphosate is the ingredient in RoundUp that is absorbed into the root system. Other products have glyphosate, too. Keep in mind that it is a total vegetation killer, i.e. whatever it touches, it will kill. It will not selectively kill just the poison ivy.
Here is more help with eradicating poison ivy including good links: https://extension.umd.edu/hgic/poison-ivy
And here is help with identifying poison ivy: https://extension.umd.edu/hgic/identifying-poison-ivy