Down the Garden Path: What to know about poison ivy

As we begin to enjoy the outdoors around our homes and communities this spring, make sure to look out for the pesky plant poison ivy (Toxicodendron radicans). Although not everyone is sensitive to this plant, many people develop an itchy, blistering rash when the plant resin – urushiol – comes in contact with the skin. Urushiol is an oily resin found in the leaves, stems, and roots of this plant.

Master of disguise

Avoiding the plant can be difficult because it masquerades as vines, groundcovers, or shrubs and is found throughout the Midwest. It can survive in full sun or shade and in wet or dry conditions. Although dormant in the winter, the resin on the stems may still transfer to clothing or skin causing a skin reaction. Pets are not affected by the plant, but if they come in contact, they can transfer the resin from their fur to the owner.

Identifying the culprit

Poison ivy can be identified by three leaves (Remember ‘leaves of three, not for me’) that are of equal size and connected at a central point. New leaves are dark green in summer and change to a reddish-orange color in the fall. There are small white flowers in the spring followed by white berries. Stems are brownish-gray and have wiry hairs. The vines can reach high into a tree and develop a stem of several inches in diameter.

Managing the threat

Once identified, be careful if attempting to remove the plant. You must wear protective clothing including long pants, long sleeves, and rubber gloves. Any gloves, clothing, or tools used and not properly cleaned can carry the plant resin. This can result in skin exposure later when you are least expecting it. The plant should be dug up with removal of roots to prevent return or treated with an herbicide that is applied to the leaves. Check with your local Master Gardener help desk or local nursery about an appropriate herbicide and make sure to apply as directed.

The plant may come back so be prepared to retreat. Keep pets and children clear of the area until certain the plant is gone. Do not burn poison ivy as the smoke may cause lung irritation. Clean gardening tools with rubbing alcohol as the resin can remain on tools for up to five years.

If you are exposed to poison ivy, make sure to wash off the resin to reduce the risk of developing the rash. Usually a degreasing agent such as dishwashing soap and water is sufficient but there are commercial products available. The poison ivy rash can usually be identified by its location in areas not covered by clothing or gloves and the linear pattern of a stem or leaf swiping the skin.

The reaction may take a day or two to appear and can be intensely itchy. The rash itself is not contagious to others, but the resin can be spread from clothing, gloves, gardening tools onto the skin of other people causing a rash to appear. For more information on poison ivy identification, watch this video and for more on protecting yourself from poison ivy, check out this tip sheet from the CDC Fast Facts.

About the author: Darlie Simerson is a certified Master Gardener and naturalist volunteer with the University of Illinois Extension serving DuPage, Kane, and Kendall counties