A friend came down with a bad case of poison ivy 2 weeks ago. She had not been directly in the weed patch, but her dog had rubbed up against the ivy during a walk and the oils had transferred to her skin from the fur. After a few days of topical treatments, she went to a physician and found a remedy that worked quickly.
There is not much you can do about poison ivy that is growing somewhere other than your property. But there are a few steps you can take to reduce the issue at your site.
The first step is proper identification. It is one of nature’s most variable plants, growing as a shrub, or a groundcover or a vine that climbs to the top of the tallest tree. It has aerial rootlets that enable the vine to attach itself to whatever it may be growing on.
Poison ivy can be found almost anywhere. It usually grows along fencerows, roadside areas, and along the edges of wooded tracts. You may find it around the home in shrubbery, flowerbeds, groundcovers and along lot boundaries. It’s those hidden patches that can leave you wondering how you got exposed.
Poison ivy is most easy to identify by its leaves, which are compound and composed of three leaflets. The leaflets can have smooth, scalloped, or irregularly toothed margins. The two lower, opposite leaflets grow on a very short or absent stalk. The third or top leaflet will be extended on a long stalk. Leaf surfaces may or may not appear oily, waxy, or warty.
There are several similar species that are often confuse with poison ivy. Virginia creeper is a five-leaf plant often found growing side by side in the same location. Virginia creeper will not give you a case of the itch, but many people mistakenly call it poison oak, which does not grow here in Indiana. Boston ivy, a common landscape plant is another look alike. Both Virginia creeper and Boston ivy have dark blue fruit later in the season.
Once established, the woodiness of the poison ivy plant makes it difficult to control. Repeatedly cutting the plant back to the ground may eventually starve the plant. However, each time you cut it, you risk exposure to the oil that causes the irritation. You can dig up and discard small plants. However, if you leave behind any portion of the root system, the plant will likely resprout.
Several herbicides are available for poison ivy control. However, keep in mind that any herbicide that will kill poison ivy may also injure any desirable plants. If the poison ivy is growing among shrubs and trees, you must apply chemical controls directly to the poison ivy plant and not to any of the other plants. If the poison ivy growth is severe enough, it may be worth sacrificing some desirable plants to eliminate the poison ivy.
Herbicide products that contain the active ingredient triclopyr are the most effective at controlling poison ivy. You can find these products at retail stores or nurseries. The products are often touted as poison ivy or brush control and are most often mixed with glyphosate.
When using these products, it is essential to thoroughly cover the vegetative parts of the plant. Be prepared to make repeated applications for complete control. The herbicide glyphosate is also effective in eradicating the pest, but again, will require multiple applications. You may also use a combination of triclopyr and 2,4-D where herbicide drift is not a factor. However, you should never apply 2,4-D in locations where other sensitive species grow in close proximity to poison ivy.
Read and understand the instructions on any herbicide label before making applications. No matter what control method you use, be careful to avoid exposing your skin to the plant. Wear gloves, long pants, socks and shoes, and a long-sleeved shirt, and launder them separately with hot water and a soap than can remove oils.
Remember: never burn poison ivy! The smoke from burning the plant contains oil particles that can seriously injure your eyes, skin, and respiratory system.
For more information, visit https://www.extension.purdue.edu/extmedia/ho/ho-218-w.pdf
By Jeff Burbrink, Extension Educator, Purdue University
