How To Identify Poison Ivy

Question From: L. O’Brien - MICHIGAN
Q: I’m on a couple gardening FaceBook groups, and there has been a deluge of questions about poison ivy, specifically pictures with the question. While I’m not great at ID by picture, I could use a few basic tips for ID. “Leaves of three” goes only so far. Other indicators used are alternate leaves, red stems, and woody stems. Which on plants just leafing out, doesn’t do much. The first detail I see is some plants have a serrated edge (weed) and some have a plain edge (more likely PI. Which of these indicators are most reliable? Do you have any to add? These are all from Facebook groups based on Michigan gardening, close to houses, in mainly urban areas (not out in forested areas) and having to do with weeds growing in gardens for the first time this Spring. Help? I have my BS in Hort from MSU, ‘07, but we never covered poison ivy, except for a look at the ancient plant in Beal Garden surrounded by red posts. I’m not even sure it’s still there.

A: In all my years of gardening I lucked out and never had to deal with poison ivy. I do know there are a number of species and some are hard to identify. If you Google pictures of poison IVY leaves you will see some of the variations. I would suggest folks send samples of the plant or plants in question to their plant and pest diagnostic laboratory affiliated with their county extension office for an accurate ID. Best And Happy Yardening, Nancy