Few garden lessons are as important as this one.
Poison Ivy
Credit: Bill Beatty/Getty Images

Skin irritation, redness, itching—you know the signs. If you've been out in the garden recently and have come away with a nasty rash, you may have gotten yourself into a patch of poison ivy. Poison ivy is a notorious garden lurker and a toxic plant. A brush of a poison ivy leaf on bare skin can send even the hardiest gardener into discomfort, even misery. It's not just bare skin, though—if the oils from the poison ivy plant touch clothing or gloves and later come into contact with skin, it's likely going to be rash city for the unlucky soul who encounters it. That's why it's essential to learn how to identify poison ivy and avoid it at all costs.

What Is Poison Ivy?

The plant commonly known as poison ivy is known by the scientific name Toxicodendron radicans. Toxicodendron is a genus of plants in the sumac family, which also includes poison oak (T. diversilobum). It's found across the South, and it likes to grow in shady environments, including in the shade created by other plants and shrubs. It hides there, awaiting unsuspecting gardeners and camouflaging itself amongst its nontoxic garden neighbors. According to The Southern Living Garden Book, "Poison ivy is common in shady areas and along the edges of woodlands. It sprawls along the ground until it finds something to climb; then it becomes a clinging vine."

"Leaves of three, let it be."

You've likely heard the singsong garden wisdom, "Leaves of three, let it be," and if you have, you'll know the warning applies to poison ivy. Poison ivy produces three green leaflets on long, hairy stems. Often, the central leaf is bigger that the two outer leaves. The three-leaf warning also applies to poison oak, which also grows both as a leafy shrub and as a climbing vine and produces three leaflets with scalloped or toothed edges.

When poison ivy is established, it produces clusters of pale green flowers which appear on the plant in spring. After the flowers appear, the plant will bear small white berries. In fall, poison ivy leaves turn red. Don't think about picking it for your arrangements though, because as The Southern Living Garden Book describes, poison ivy is toxic year-round, and "plants are just as poisonous in winter as when in leaf." This is because every part of the plant contains and emits a resin known as urushiol. When it touches skin, it causes a severe reaction called contact dermatitis. Ouch!


Never, ever burn poison ivy. The smoke is toxic, and inhaling it can cause an intense reaction, making you terribly sick. According to The Southern Living Garden Book, the best way to rid your garden of poison ivy and poison oak is to use an organic or chemical herbicide.

WATCH: Grumpy's Guide to Poison Ivy (& Lookalikes!)

What poisonous plants would you like to learn to identify? What pesky garden irritants do you find yourself running into again and again?