Control Those Weeds: Poison Ivy

Poison ivy (Toxicodendron radicans) is a trailing or climbing vine. It is probably the most common cause of dermatitis to gardeners, campers, and hikers.

It is found in almost all of North America with the exception of a few southern and western states.

Range of Poison Ivy

The irritant oil of poison ivy is found in every plant part (not just the leaves). Poison ivy is famously three-leaved. Aerial roots give climbing vines a hairy appearance. Dermatitis can occur from direct contact or from contact with exposed clothing, pets, or smoke from brush burning.

Dermatitis from contact

lt is known by several different names: three-leaved ivy, poison creeper, climbing sumac and poison oak.

Although it can grow as a self-supporting, erect woody shrub, its usual growth habit is as a vine running along the ground, or growing on shrubs and trees. The vines can grow to several inches in diameter over a period of years.

Poison ivy has three leaflets occurring alternately along the stem. Leaflets are usually smooth, but may be either a dull or glossy green. Leaf edges can be smooth, toothed, and/or lobed. Leaves on the same vine often have a number of color and leaf edge combinations. Because there are no distinguishing characteristics to warn an unsuspecting individual that a vine is poison ivy, the old saying of "leaflets three, let it be" should be remembered.

Poison ivy plants produce oil called urushiol, which is usually capable of causing severe skin irritations the year around. There is always the danger of transferring some of the oil present in the leaves, stems, fruit, roots or flowers of the poison ivy plant to the skin. Although contact with the plant is normally the method of exposure, an individual can also be exposed by handling clothing, tools, objects or animals which have become contaminated with the oil or by smoke from burning the plants.

Control

Burning is not a recommended method for eradication. Burning produces soot particles which carry the oil into the air. Individuals coming in contact with the smoke will experience severe cases of poisoning.

Poison ivy can usually be dug out when the soil is wet and there are only a few plants. However, attempts to remove roots from dry soil are futile. Pieces of root remaining in the soil may sprout and replace the original plants.

Repeated cutting of the plant back to the ground surface will eventually starve the root system and the plant will die. However, repeated cutting increases the chances of exposure to the toxic oil.

Several herbicides are effective in the control of poison ivy. There are numerous brand names for the herbicides. The label on each product will list the name of the active ingredient and its concentration.

If the chemical will control poison ivy, it will be stated on the label. The label should list poison ivy and give the proper rate to be applied, along with other details on proper application procedure. Several commonly used herbicides that control poison ivy are: Glyphosate, Amitrole, 2,4.D, Triclopyr.

For those of us who are battling weeds, no matter which one; fall is the perfect time to go after and get rid of them. Herbicides work best at this time of year as weeds are storing energy for the winter in their roots. The herbicide is absorbed more readily than at any other time of year. Many weeds will require multiple applications so get an early start before frost arrives.