Ask the Clark Gardener

Dear Fellow Gardeners:

October 13, 2011. When I started working at Fanny Dwight Clark Memorial Garden, Inc. in 2008, I was still pursuing my horticultural degree from Farmingdale State College. I took a required Turf Management course in the Fall semester of 2008. I enjoyed that course the least of the ones I took for my degree. One of the class assignments was to write an essay and there were very liberal guidelines as to topics that the students could choose. So, I chose a topic that I was interested in with a very tenuous connection to turf management: Poison Ivy. Working at Fanny Dwight Clark Memorial Garden, Inc. came with a major association with poison ivy and I wanted to learn more about it. I recently came across this essay in my files and I thought that you might find it interesting. Here it is, with a few editorial changes:

“Whatever you do, watch out for poison ivory,” I was told by a co-worker while orienting me to my student internship at a small botanic garden this last summer, and extending into this fall. I thought that this was an odd warning, but I took it to heart. All that first day, I was ever on the alert for toxic tusks that might be hidden under bushes, lying next to trees or hidden under garden debris. I found no poison ivory. My reaction ranged from disappointment to vast relief. I was disappointed because I figured there had to be a lucrative market for the ivory, even if poison, and I would finish the summer with untold wealth. I was more relieved though, because I also figured that poison ivory must come from some pretty sick, crazed elephants and I feared encountering them.

The next day my boss returned from taking a vacation day and she showed me around a bit more. “Whatever you do, watch out for poison ivy,” she said. “And there is some right over there,” she continued. Well, I must have looked mighty confused, but the light was beginning to dawn. My boss continued, “You do know what it looks like, donít you?” Well, I didnít, and recovered enough to have the presence of mind to simply admit it and not make any reference to crazed elephants. Thus began my education on Toxicodendron radicans, commonly called poison ivy.

What my boss showed me was a plant growing close to the ground, with glossy green leaves in a configuration as in the picture above. By the end of the day, I felt that I could pick out poison ivy at ten paces.

Poison Ivy in Fall Poison Ivy at the beach
Poison ivy in the Fall   Poison ivy at the beach

On the third day of my internship, my boss was giving me an assignment, and I heard it again: “Whatever you do, watch out for the poison ivy.” And then, “In fact, thereís a whole mess of it near your feet.” I looked, and what I saw was a plant with a leaf configuration much like what I saw the day before, but the leaves were larger and noticeably duller. So, the lesson learned that day was that whatever other rotten qualities poison ivy has, it was sneaky. Some poison ivy leaves are notched, some are not. Some leaves are shiny, some are duller. Poison ivy leaves can be of different sizes. Poison ivy can climb, it can creep, it can even form a true shrub. The leaves get good fall coloring, and the plants can even get berries.

To my coworkers, poison ivy was the botanical equivalent of the ogre in the woods, the troll under the bridge, or the monster in the closet — avoid it if you can but if you have to deal with it, approach it carefully and in fear. Poison ivy is an innocuous looking plant, actually rather fragile. However, if the plant is torn or broken, an oil inside called urushiol may be secreted. Urushiol can cause a horrible allergic reaction. The reaction could result in an annoying itch over a small area, or it could involve large areas of your body with red sores that itch like crazy. Here are some other gruesome facts:

  • Urushiol remains in stems, roots, leaves, flowers, and fruit of poison ivy throughout the year.
  • Urushiol is insoluble in water.
  • Urushiol can retain its potency for long periods of time.
  • A rash from urushiol can occur without direct contact from the plant. Touching items that have been in contact with poison ivy can cause an allergic response.
I have testimony from another one of my coworkers that the latter point is certainly true. Her husband is a nature enthusiast who apparently often makes his way through relatively wild outdoor areas. After borrowing his car one day, my coworker came down with a nasty rash on her back which seemed to be from poison ivy. After vainly trying to figure out when she was exposed to poison ivy, my coworker discovered from her husband that he had walked though infested areas and threw some belongings on the carís seats when he returned from his walk. It seemed probable that urushiol got transferred from his belongings to the carís seats, to my coworkerís clothing, and ultimately to her back when she borrowed the car. After that incident, my coworker did not drive her husbandís car for about a year. [Of course, a contributing factor to her decision not to drive his car was another occasion when an escaped, missing (unknown to her) snake of his showed up under the brake pedal while she was driving.]

One other nasty aspect of urushiol is that one can apparently be immune to the allergen, but that is not necessarily a permanent condition. That immunity can be lost through repeated exposure, for example. Yet another one of my coworkers had personal experience regarding this aspect of urushiol. He recalls that he was immune to the effects of poison ivy until he ďrolled in itĒ when he was 33. I did not ask for any additional details as to why one would roll in poison ivy, as I felt that I might be dealing with one of those occasions where I would find out more than I wanted to know.

The abhorrence of poison ivy was so great where I worked that I soon realized that I could turn it to my advantage. If a task became too exhausting, boring, or if it was just too hot to work, I could have usually found a patch of poison ivy nearby, pointed to it sadly, stared at my shoes, and whimpered that I just couldnít go on for fear of exposure. Nobody would have held it against me. I could have done that, but my boss usually told me up front to work around infested areas.

Ultimately, of course, I came to areas in the gardens that I wanted or needed to clean out and had to face the issue of how to get rid of the poison ivy. Chemicals were one choice. But, the option that I finally personally chose to clear areas of poison ivy was to manually pull it up. After all the hype from my coworkers regarding poison ivy, I chose this option with a lot of trepidation. I wore plastic gloves. I avoided contact of the plants with any of my clothing, my tools, or my work cart. I disposed of the pulled up plants and the plastic gloves in plastic bags, and immediately put them in the dumpster. These precautions were taken to protect me, my coworkers, and the sanitation man who emptied the dumpster.

One option to eradicate or dispose of poison ivy that is universally condemned as stupid is to burn it. Breathing the smoke from burning poison ivy or being in contact with the smoke can make one seriously ill, possibly even landing one in the hospital.

Once I was done with an area, I immediately washed my arms and hands with a product designed to help to remove urushiol from the skin if used early enough. Other recommended procedures for trying to get urushiol from the skin is to immediately flush a contact area on the skin with cold water, washing the skin with hot water and borax, or swabbing an exposed area with alcohol.

Despite all precautions taken, sooner or later one may get a reaction to poison ivy. Iím not talking from personal experience now, as I only did manual weeding of poison ivy for one day and suffered no ill effects. Whether that is from immunity or taking protective precautions, Iíll never know. My co-workers are practically chanting, “Youíll see! Youíll see! It will get you some day.”

It could take anywhere from about 12 hours to 3 days for a rash to appear after being exposed to poison ivy. The rash per se is not contagious, nor does any fluid from broken blisters caused by the rash spread the rash – unless there is urushiol still around to cause exposure. Once a rash occurs, some claim that the juice of jewelweed (Impatiens biflora) and plantain (Plantago major and P. lanceolata) will soothe the rash. Hot showers can ease the itch for a time. Spraying with a deodorant containing aluminum supposedly also can cause some relief. There are over the counter products that claim to relieve the rash. There are also prescription remedies that can make the rash go away quicker. The rash lasts from around a week to 3 weeks.

Believe it or not, poison ivy actually does seem to have some benefits:

  • Birds and other animals use poison ivy as food.
  • Poison ivy plants can help to prevent soil erosion.
  • Iíve seen some reference to medical uses for poison ivy, including use in an external treatment for arthritis. However, the medical references that I found were somewhat vague or unconvincing.
In closing, I cannot help but wonder if elephants can use poison ivy as food. If so, would their eating poison ivy result in poison ivory?

Well, guess what. Since I wrote this essay, I have since had a couple of rounds of mild reaction to poison ivy – right around my wrists where my disposable gloves end. Areas where visitors frequent are generally clear of poison ivy, so donít let fear of the itch keep you from visiting. And, just a reminder, if you have a comment, horticultural question, or general question about Fanny Dwight Clark Memorial Garden, Inc., remember to send them to me at

The Clark Gardener

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