Poison Ivy

It’s one of the worst possible itches, and most of the time, you don’t even know where or how you picked it up. Poison ivy, Rhus radicans, is a native plant that is usually less than welcome in the suburban yard or garden.  While its fruits provide valuable food for birds, its oil, urushiol, secreted by its leaves, stems and roots causes an allergic reaction in many humans.  Indeed, the birds are the usual suspects in spreading the plant in garden beds or at the edges of the property. It thrives in both sunny and shady situations, in rich woodlands and in barren waste places. Poison ivy has the irritating habit of insinuating itself amidst other plants, perhaps as a survival mechanism. Often it will climb the nearest vertical structure, including trees and telephone poles. Or you may encounter it running along the ground.

Learn to recognize its “leaves of three” and “let them be” when walking in the woods. Another useful adage is, "Berries white, poisonous sight." The leaves are alternate on the stem and are divided into three leaflets. The leaf surface may be either glossy or dull green, and either smooth or somewhat hairy. Leaf color may vary due to the degree of shade (and weather conditions) from light to deep green, yellow-green or even red. Autumn color is yellow and bright red before the leaves drop. A white berry-like fruit remains through winter. At all seasons of the year, poison ivy causes skin irritation in humans. Domesticated pets may also come in contact with the plants and spread the harmful oils. If you wash with water or a wet-wipe within ten minutes of skin exposure the risk of developing a rash is greatly reduced.

What if you want to clear a neglected corner that is infested with poison ivy to make a new garden space? Or what if a few seedlings of poison ivy are starting to take a toehold in an established shrub border or perennial bed? Is there an effective, alternative way to eradicate it without using herbicides?  The answer is a resounding “Yes.” Poison ivy will eventually die out if it is repeatedly clipped to the ground by mowing. In rural areas, grazing animals, such as sheep or goats, can clip it quite effectively. On suburban properties, after clipping it yourself, place a smothering mulch of cardboard topped with wood chips, bark mulch or shredded leaves over the area. This can be a very effective way to eradicate large patches. Small seedlings may be repeatedly hand-pulled using strong, non-absorbent protective gloves. Tyvek painting suits can help prevent exposure to the urisiol oil. Be sure to search down to at least six inches to find the running roots. Visit the area again within two weeks to check for resprouting.  Or try the “Glove of Death” technique, a chemical-resistant glove with an absorbent glove slipped over it. Dip this glove in a commercial organic weed killer (based on citric acid, clove oil and/or vinegar) and wipe on the foliage.  Repeat as necessary to completely kill the poison ivy.

Vines growing up fences or trees can be cut at ground level. Several days later, pull out as much of the wilted plants as possible. Or wait until winter when they can be pulled out without damaging delicate branches and will contain fewer oils.

When pulling out poison ivy, use long plastic bags or impermeable protective gloves to cover hands and arms up to the shoulder. Invest in a bottle of Tecnu™, a pre- or post-handling product that helps dispel the effects of any oils you may come in contact with during the cutting or pulling operations. Also, Avon makes a pre-handling product. (Read all ingredients of these carefully as they may not be suitable for sensitive skin.)  Gather all plant parts in bags and dispose of the entire collection in the trash. Wash gloves completely with Fels Naptha™ soap, an old-fashioned, yellow-colored soap, and hang to dry. Or, better yet, discard them. Under no circumstances should you burn the poison ivy or pour boiling water on it, as the poisonous oils will volatize.

by Priscilla Williams, Michael Nadeau, and Sarah Little