The Itchy Truth About Poison Ivy

poison ivy vine climbing a tree
Poison ivy uses hairy aerial roots on its vines to cling to trees. Photo: Betty Marose

It starts with a twitch and an itch. Then it grows into full-blown scratchiness and dreadful knowing. You have poison ivy. Again.

I tip my hat to those immune to the maddening rash that contact with this plant brings. You are indeed the Fortunate Ones. The rest of us will try to quiet our whimpering.  

It pays to know the enemy. Poison ivy is a perennial plant that can climb trees as a vine, form a shrub, or snake over the ground. It spreads by seeds and rhizomes, sneaky underground stems that help it form colonies. 

A native plant whose berries feed over 50 species of birds, poison ivy has glossy leaves, attractive berries, and striking fall color. If it weren’t for the itch, we’d love it. 

The key to managing poison ivy is learning to recognize it. “Leaves of three, let it be,” is a wise adage. Most poison ivy has three pointed leaflets that form one compound leaf. 

young poison ivy plants have three leaflets
Poison ivy has compound leaves with three leaflets which inspire the phrase, “Leaves of three, let it be.” Photo: University of Maryland

Nearly all poison ivy leaves have wavy or toothed edges, but some are smooth. In spring, they are shiny and reddish, turning green as they mature. In the fall, leaves turn yellow, orange, or red.

Another giveaway is poison ivy’s hairy vines bristling with aerial roots that help it cling to trees.

Lookalikes abound. Virginia creeper has similar leaves with 5 leaflets to each compound leaf. Box elder seedlings have nearly identical 3-part leaflets. When in doubt, steer clear.

To help you tell the real deal from imitators, we’ve created a handy identification guide with photos here.

Every part of the poison ivy plant – leaves, stems and roots – carries an oil called urushiol that irritates skin. Even dead plants can cause a rash.  

Symptoms of exposure – itching, burning, swelling, rash and blisters – can show up a few hours to a few days after contact. You can also get it from tools, clothing, or pets.  

How do you prevent the torment that is a poison ivy rash? Learn to identify and manage the plant and treat yourself after possible exposure.  

Cover up well with long pants and shirt and gloves and dig out, bag, and trash small plants. Or spot-spray foliage of small plants with a non-selective herbicide with glyphosate, being careful to avoid desired plants.  

Penn State University advocates using the “glove of death.” Don nitrile or other chemical-resistant gloves, then cotton gloves, and wipe a glyphosate solution onto small plants.   

If poison ivy vines are growing up your trees, cut the vines to starve the top. Never burn poison ivy. That can send its irritating oils into the lungs and you to the hospital.

The best time to treat poison ivy is early to mid-summer when it’s actively growing, but now is not too late. After contact, wash clothing separately from other laundry and carefully clean tools.  

Now you have the tools to identify and manage poison ivy. Forewarned is forearmed. And much less itchy.

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension. This article was previously published by Herald-Mail Media. Read more by Annette.

2 thoughts on “The Itchy Truth About Poison Ivy

  1. Michael Scepaniak September 30, 2020 / 4:53 pm

    Whenever I start to develop a rash from poison ivy, or if I even _think_ there’s a chance I touched some poison ivy, I use Tecnu Extreme. It does a fantastic job removing the oil and also drying out the rash. Additionally, it contains silica (sand), which helps to numb the itch of the rash. I keep two bottles on-hand at all times.

    • Annette Cormany October 5, 2020 / 10:55 am

      Thanks for sharing, Michael. I’ve not used Tecnu Extreme. Good to know it’s been so helpful.

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