Michigan State University Extension
Home Maintenance And Repair - 01500592
06/24/03

Heed all warnings. Check with your physician if you have any concerns regarding your personal health risk. Revised by Tom Ellis, M.S., Department of Entomology

Poison ivy (Toxicodendron radicans) is found in nearly every part of Michigan. lt is known by several different names, such as 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 slender 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 margins (edges) can be smooth, toothed, and/or lobed. Leaves on the same vine often have a number of color and leaf margin  combinations. It is possible, however, that all leaves on a vine will have the same general character. 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.
 (Vis. 1)

The flowers of poison ivy are typically inconspicuous and arise in clusters above the leaves. The berrylike fruit has a smooth waxy appearance and is gray to white in color. After the leaves drop in the fall, the berries are a distinct identifier the poison ivy plant. As a vine climbs shrubs and trees, it produces numerous "aerial roots" which attach to the tree or shrub. The "aerial roots" give the vine a characteristic appearance often described as looking like a "fuzzy rope."

Poison ivy plants produce an oil called urushiol, which is usually capable of causing severe skin irritations the year around. There is always the potential 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 plan 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.

Two general methods of control of poison ivy are culture and chemical. Cultural methods should not be attempted unless the individual is tolerant to poison ivy. Individual sensitivity to poison ivy varies greatly. Natural immunity is originally present in all persons,  but is lost after the first contact with the oil. Subsequent contact with the oil will result in skin irritation, although severity of the reaction may vary. Therefore, always take care when attempting to eradicate this plant. Individual must also be careful when us in chemical methods so that desirable plants are not mistakenly killed or injured. ALWAYS READ AND FOLLOW LABEL INSTRUCTIONS FOR ANY HERBICIDE USED AROUND THE HOME.

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. Plowing is also of little value, since the disturbed root systems will sprout. 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. Most of the products listed in this bulletin can be found in premixed or easily used formulations at local home and garden centers. Other chemical products will control this plant, but may not be registered for use around the home and are designated as Restricted Use products (RUP). If these chemicals are required, contact your local county Extension office for procedures on becoming a certified application and for the location of a local commercial pesticide distributor for product availability.

There are numerous company and store brand names for the herbicides which control poison ivy. 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 Other chemical products may also be used to control poison ivy. Although they may not be registered for residential use, they are available for use in other situations, such as along fence rows, in fields, or in wooded areas. These products include dicamba (Banvel),  hexa-zinone (Velpar), 2,4-D ester + 2,4-Dp ester, picloram (Tordon), and sulfometuron methyl (Oust).

For specific recommendations on the use of these chemicals, contact your local county Extension office, found under local government in the phone book

References

This information comes from Michigan State University Extension bulletin E-1517, Poison Ivy Control.

This information is for educational purposes only. References to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned. This information becomes public property upon publication and may be printed verbatim with credit to MSU Extension. Reprinting cannot be used to endorse or advertise a commercial product or company.

MSU is an affirmative-action, equal-opportunity employer. Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Thomas G. Coon, Director, MSU Extension, East Lansing,MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

This information.was reviewed as of June 2008.  For more information about the contents please contact costner@msu.edu for webpage problems strausc@msu.edu .