Read an Excerpt
Eastern Poison Ivy (Toxicodendron radicans)
Overview: Although this native perennial can grow as a shrub up to 3 feet tall, Eastern Poison Ivy is more typically a vine that can be up to 60 feet long. Stems are woody and ropy, and develop thick aerial roots that attach to supporting plants or structures with fine, dense rootlets (see small photo at right).
Where You’ll Find It: An adaptive plant, Eastern Poison Ivy grows in sun or shade; it prefers moist areas with good soil but tolerates drought. It is most common in open woodlands and woodland edges but also grows along fences, on trees and climbing up buildings in more habited areas. Eastern Poison Ivy is found throughout our region except the Dakotas, where it is absent or rare. It is listed as a noxious weed in Minnesota.
Leaves: Three-part compound leaves grow on the ends of long, thin stalks attached alternately to the main stem. The stalk of the central leaflet is longer than those of the two side leaflets. Leaflets are egg-shaped and typically 2 to 4 inches long, occasionally longer. Edges may be smooth or have coarse, irregular teeth or wavy edges; shallow lobes are sometimes present. Leaflets turn red in fall.
Flowers/Fruit: Flowers grow in large, loose clusters in leaf axils. Each is about 1⁄4 inch across, with 5 greenish-white triangular petals that fold backwards and 5 brown-tipped stamens. The round, ridged berries that follow are about 1⁄4 inch across; they are greenish when immature, ripening to dull white. The berries are toxic.
Season: Plants flower from late spring to midsummer; fruits ripen in fall and may be present through winter.
Other Names: Poison Vine, Rhus radicans.
Compare: Western Poison Ivy (pg. 60) is a tender plant with similar leaves. Flowers are 1⁄16 inch across with yellow-tipped stamens, and grow in smaller clusters. Plants are typically 6 to 12 inches high, but may be up to 3 feet tall.
Getting Rid of It!
Never burn Poison Ivy, as the smoke it produces will cause severe respiratory distress in anyone who breathes it. Always wear gloves, long sleeves and pants when dealing with Poison Ivy; a disposable coverall is even better. Pull down the vines and cut them to ground level, transferring them to plastic bags for disposal (do not compost the plants). Dig out the roots if possible; otherwise, paint the stump with glyphosate. Rinse all tools with water, then wash with rubbing alcohol. It may take a few years to completely kill the plants.
What’s It Good For?
See the comments for Western Poison Ivy on pg. 61.
