But a rhyme comes to mind when I see this plant that goes “Leaves of three let it be”. And by “let it be” we mean “do not touch this plant!!!”. A little contact now with this little plant will create a lot of pain later.
I have had horrible rashes from this plant in the past. They have been bad enough at times for me to go to the doctor. I therefore am extra cautious about seeing it, handling it, and destroying it. I am not a doctor or expert on these plants. But, I have done some research over years on the plant and how to control it since it is an ever-present danger to a gardener. I want to share the steps I go through when I encounter this plant.
Poison Ivy, Poison Oak, and Poison Sumac all use the same substance to create a contact dermatitis on the skin of some people. So, in regular language that means, it creates a rash. But this rash comes with burning, itching, and oozing blisters. The rash is technically an allergic reaction to an oil in the plant called urushiol. Since it is an allergy some people are immune. But that immunity can come and go during a lifetime.
I cannot have this plant growing in my herb garden so I must remove it somehow. But I have to do that while trying to not get the oil on me. I usually wait to remove the poison ivy until I am done with all the other work I was doing for the day. That is because I will wash all the tools, gloves, and my hands after I am done. Some sources say urushiol can be removed with soap and water or rubbing alcohol. Some say it is possible that a reaction can be prevented if exposed skin is washed within 15-30 minutes of exposure.
It is important to note that these plants should never be burned to dispose of them. Urushiol oil will travel in the smoke. From there it can be breathed in or land on the skin. The best method is to put the plant in a tied up plastic bag and throw it in the garbage.
When I traced the plant back to the roots I also found that it was much larger than it looked at first. The first picture shows maybe three groups of leaves. I can see way more in the picture below. The plant was much longer and had runners with more roots. Had I missed any of these other parts of the plant, it would have kept growing back. I should point out that all parts of the plant have the oil in it. Leaves, stems, and roots all cause the reaction.
Some good sources of information on these plants that I have found are:
American Academy of Dermatology, https://www.aad.org/public/diseases/itchy-skin/poison-ivy-oak-and-sumac#causes