How to Recognize, Respect, and Reduce Poison Ivy

Did you know that humans are pretty much the only animals who get severe skin reactions from Poison Ivy? Many other animals not only tolerate the plant, but are fed and nourished by it. Poison Ivy (Rhus toxicodendron or Toxicodendron radicans) is a native North American plant that serves an important role in various ecosystems. Among modern humans, though, it often garners a sense of loathing and dread, since the plant seems to harm us rather than benefit us. I admit I’m pretty tired of seeing it everywhere in the Wissahickon and Fairmount. But ultimately, the goal of this article is to allow knowledge, understanding, and humility to transform the hatred, anger, and fear into a kind of deep respect. That respect will, of course, include eco-friendly ideas for coping with it on your property, how to avoid the rash, and what to do if you have been exposed. 

History, Botany, and ID

It behooves us to understand some botanical history and the roles of Poison Ivy (PI) in the ecosystem. PI is part of the Anacardiaceae family, commonly known as the cashew family. Other members of this plant family include mangoes, pistachios, and the urushi tree (Toxicodendron vernicifluum), which provides sap used in creating Japanese lacquerware. This sap contains the urushiol oily resin, the very same substance found in Poison Ivy. It is the urushiol that causes that horrible rash on human skin. More on this invisible spreader below. 

PI is a robust and resilient plant with many variations—it can take a shrubby, vining, or ground cover form and the leaves can also vary in their appearance. “Leaves of three, let it be,” is a pretty good reminder, but you should specifically look for the middle leaf on a slightly longer stem, jagged edges (though some may not be very jagged at all or look more like a mitten), and possibly a reddish stem. The vining type is very common in the eastern U.S.—look out for hairy stems/aerial roots climbing up trees and fences, which are just as poisonous as the leaves. 

One last weird piece of history: William Bartram (whose last name you may recognize from Philly’s Bartram’s Garden), listed Poison Ivy seeds in his late 1700’s catalogue of “American” plants he would sell to plant-collectors in Europe. Apparently, some people did, in fact, find ornamental value in this dangerous plant. 

Food and Function

Many animals consume various parts of PI, including the leaves, stems and berries. Animals who enjoy this food source include rabbits, goats, bears, deer, raccoons, muskrats, robins, crows, bluebirds, quail, woodpeckers, wild turkeys, and a variety of insect pollinators.

We know that Poison Ivy often shows up in disturbed soil, and because it can cause such an uncomfortable rash for humans, an interesting theory is that PI serves as a sort of “keep out” sign. It makes us more cautious, slow, hesitant—less eager to enter a particular area of the woods where PI abounds. That place needs time to heal, perhaps. For me, that caution is also respect. It requires me to hone my observation skills and look around carefully. It means I don’t get to touch or take just anything I want from the land. If I want to walk barefoot in the woods, I must heed the “keep out” signs vigilantly.

But perhaps more fascinatingly, did you know that increasing levels of of carbon dioxide in the atmosphere generally cause growth enhancement in vines? A six-year study at Duke University showed this to be especially true for Poison Ivy—elevating levels of CO2 in the air are responsible for increasing the growth rate, biomass, and allergenic intensity of urushiol in PI.

Wow, we knew the CO2 was bad for climate change, but who knew it was also making PI grow bigger, stronger, and more allergically potent?! If you needed yet another reason to fight for green policy and culture changes individually, community-wide, nationally, and globally–there you go.

For me, that caution is also respect. It requires me to hone my observation skills and look around carefully. It means I don’t get to touch or take just anything I want from the land.

Some aggressive vines end up choking out and killing trees. This tree is all vine, no leaves of its own. Human behavior has led to increased CO2 in the air, which leads to even more aggressive growth of vines.

Managing PI on your Property

It can be a real bummer to discover Poison Ivy on your property, especially in areas where you or pets or children may wish to play or walk, or in areas where you’d like to be planting desirable plants or otherwise maintaining a garden. Here at Eating for the Ecosystem, we aren’t in favor of using chemical herbicides to kill the plant. If you are really set on clearing a given area of PI, the methods we usually employ are as follows:

-For smaller areas or single plants, dig out the plant by the root if you can (be sure to see precautions below, and work very carefully). 

-For larger areas, you might first attempt to dig out as much as you can, while wearing protective gear. Consider a painter suit or nonporous clothing to shield your skin. Then, you can lay a sheet of black plastic over the designated area to continue to inhibit growth of any vegetation in that area. Over time, without sun or water, the plants should die. You should still exercise caution when digging or planting in that area later, in case any roots were left behind. 

Thinking again about the scientific findings on PI growth, continuing to find ways to reduce CO2 emissions and improve carbon sequestering in soil can help halt the rapid spread and proliferation of PI. 

Precautions and Post-Exposure Remedies

Precautions
  1. Observe and actively look for PI nearby; identify where it tends to grow.
  2. Do not touch any part of the plant with bare skin.
  3. Do not burn PI— the smoke can irritate the lungs.
  4. If the plant must be touched, use thick non-porous gloves and either wash them well when you are done or discard them if disposable.
  5. Be careful to avoid letting your clothing, backpack, cellphone, tools, etc. touch the plant—the oil can get on these objects and be subsequently transferred to your skin. The urushiol can stay on surfaces for up to five years if not washed off properly! If you know any objects or clothes brushed a part of the plant, wash thoroughly. Use rubbing alcohol to wipe down tools and phones, etc.
  6. Be careful on rainy days; water dripping off of a poison ivy leaf can contain urushiol in it.
  7. Be careful if intending to touch or harvest a plant dwelling nearby a PI plant.
  8. If you know your skin has touched any part of the plant, wash immediately (within the first 10 minutes) with Tecnu or similar product. You can also wipe skin with rubbing alcohol. If that is not available, it can also be effective to wash in a cold creek— use sand or silt granules to rub the skin as you wash, this will more effectively dislodge the oil.
  9. Jewelweed is a plant that often grows near PI and is the most effective remedy. The sooner you use it the better (you can just mash it up and rub it on the area you think was exposed).
what to do if you get a rash
  1. Jewelweed is also effective if you already have a rash. I’ve had success turning it into a green paste (blended with other goodies like plantain and witch hazel) and applying it every night to the affected area. I then wrap the area in gauze so that the paste doesn’t get anywhere else, and also so that I do not scratch the blisters.
  2. Even if you don’t have jewelweed and opt not to make your own natural remedy, store-bought remedies like drying Calamine can be helpful.
  3. In all cases, I have found wrapping the rash with gauze to be the most effective way to stop me from scratching the blisters. Less scratching also makes it less consistently itchy.
  4. Try homeopathic pills to reduce the severity of the symptoms (I use Hyland’s brand), which contain tiny amounts of Rhus toxicodendron. This is not the same as the folks who will tell you to make yourself immune by eating parts of the plant. People do that, and it works for some people, but it also has led to bad situations for others. I don’t recommend this method as of now, but then, I haven’t tried it myself.
  5. Once again, make sure you have washed everything well, including your entire body and any clothing and objects that may have contacted the plant directly or your skin after you had touched the plant.
  6. For those with severe allergies or with very large areas of rash, seeking medical attention may be your best bet. If you have access to a doctor you trust, seeking their help and advice is recommended.

Teaching Climate Change

Sherrilyn Billger, PhD and Andrew Smith, PhD will present two companion pieces at the Next Earth: Teaching Climate Change Across the Disciplines conference June 10-30, 2019. This is a nearly carbon-neutral (NCN) conference presented by the Environmental Humanities Initiative at UC Santa Barbara. For more information about these projects, please read the abstracts below.

The Philosopher and the Entrepreneur: The Pedagogical Significance of a Symbiotic Relationship

Andrew F. Smith and Sherrilyn M. Billger

How many environmental philosophers do you know who’ve had the opportunity to develop a symbiotic relationship with an entrepreneur? In our case, the entrepreneur—a specialist in restorative landscaping and forestry—opened the philosopher’s eyes to one important way in which care for the needs and interests of urban and suburban landbases provides a tangible inroad into addressing climate change. This has had a marked effect on both his scholarship and his teaching. Reciprocally, the philosopher offered a theoretical framework to the entrepreneur, rooted in a defense of plant sentience and our embeddedness in the living community. This gave birth to the name of her business. It’s also informed how she advertises it to draw attention to the ecological and climatological importance of cultivating people–plant relationships.

In this presentation, we tell the story of the pedagogical significance of this symbiotic relationship. The philosopher offers insights into how the entrepreneur’s hands-on work aimed at restoring ecosystems inspired a book project that’s influenced his teaching inside and outside the classroom. This has proven particularly beneficial when focusing on steps students can take to work with our distant green relatives to mitigate the worst effects of climate change. In turn, the entrepreneur has found the philosopher’s theoretical framework invaluable for teaching clients and employees how to be nurturers of the land.

Take it Outside:  Eating for the Ecosystem

Sherrilyn M. Billger and Andrew F. Smith

Most of us have strong (occasionally clashing) opinions about to best redress climate change. Whether we debate as polite discourse, lively classroom discussion, or proverbial bar-room brawls, we need to step back and take it outside. To wit, this collaboration between philosopher and entrepreneur presents strategies for enhanced learning by taking students outside.

The philosopher’s pedagogical methods in the comfort of the classroom encourage students to engage with climate issues intellectually. They obtain an essential foundation, understanding theoretical issues, scientific underpinnings, and cultural context, but are unsure about how to translate what they learn into what they can do. This frequently leads to depressive overwhelm that can fortunately be alleviated through interactions with living communities in local ecosystems. Such outings provide experiential learning about interdependence, soil health, social justice, invasive species, storm water, plant tending, etc. To be clear, what is needed is not vocational training per se, but a link between the theoretical and the practicable. 

Climate change isn’t just happening out there, in the rainforests, low-lying islands, and Arctic ice sheets. It’s happening down the block where the storm drains overflow, in the park overgrown by invasive vines, and among the street trees outside the classroom window. This presentation will lay out essential elements for connecting theoretical foundations to experiential learning. We will include footage from our out-of-the-classroom activities.  

What we eat matters

What we already know

The majority of food available to us is heavily processed and shipped long distances. Conventional produce has often been sprayed with chemicals that may cause cancer. We know that diets high in fresh produce are healthier, and many consumers demand organic options. Locally-produced food is generally fresher, and prevents large transportation costs, including the pollution that transportation generates. CSAs are growing, farmers’ markets are booming, and community gardens are popping up all over the city. We’re moving (slowly) in the right direction.

We know climate change is real. We know monoculture crops are particularly vulnerable to the effects of climate change. And we know that the political climate directly affects environmental regulations and therefore the quality of our air, water, soil, and food. Now is the time to take action. Now is the time for every single one of us to improve the way we eat.

But why should I grow my own food?

Growing your own food is a patriotic and revolutionary act. When you grow your own food, you have greater control over what ends up on your dinner plate. You can pick the varieties you like best, you can use organic methods, you can eat the veggies at their peak ripeness. Nothing tastes better than a freshly picked vine-ripened (in my opinion Brandywine) tomato.

If you are a CSA member or buy produce at a farm stand, growing a few of your own edibles is a great complement. The CSA and farm are indeed local—which is great!—but nothing’s more local than your back door. And maybe they don’t grow your favorite hot pepper. At the height of the harvest, vegetables like snap peas and string beans should be picked every few days. You can claim your bounty at its absolute peak.

When’s the last time you bought a head of lettuce with a few brown leaves? How about a strawberry with a mushy spot? An oddly shaped tomato? We demand visual perfection from the produce we buy, and as a result, we waste a lot of perfectly good food. You are probably more forgiving with edibles you grow yourself. You’re likely to pull off (and compost) the brown lettuce leaves, cut out the mushy strawberry spot, and use the tomato anyway. Let’s embrace imperfection and reduce waste!

You can make our ecosystem healthier

By growing more of your own food, you add more green to our city, which not only looks nice, but also helps improve air quality. Adding new garden beds and containers chips away at the ubiquitous concrete surfaces that perpetuate our ongoing runoff problem. Your garden can enhance biodiversity, feed pollinators, and improve your own connection to the natural world that surrounds us. And fresh produce is just plain yummy.

Why “eating for the ecosystem”?

I started Eating for the Ecosystem because I am determined to change what we grow and how we grow it. I know we can choose plants and designs that strengthen our ecosystem, while looking beautiful and providing us with food. And we can do it affordably.

The company name arose from discussions with my husband about his second book, A Critique of the Moral Defense of Vegetarianism. One of his points matches one of my long-held beliefs: that “[h]ow plants are treated in the process of cultivating and gathering them for food matters morally” (p. 31). To me, plants are people too.

We both consider what we consume to be a moral decision, and we constantly re-examine our choices. We believe that the best metric for weighing these choices is the effect we have on our ecosystem. “[T]he world is full of people, only some of whom are human. Plants and other-than-human animals may be people, too. Moreover, we maintain a special bond with, and specifiable obligations to see to the needs and interests of, our landbase and all the people who live on it and in it” (p. 8). We have a bond with, and obligations to, our ecosystem.

Myriad factors can drive a person’s food choices, whether health effects, genetic modification, price, availability, treatment of animals, synthetic chemical use, sentience, or environmental impact. I frankly don’t care whether other people have the same diet I have. I do care whether people think about what they eat and how their food choices impact their ecosystem. And I want to make it easier for anyone to make consumption choices that match their values.

I want to encourage eating for the ecosystem: growing more food in urban settings, selecting diverse plants that support local animals and insects, turning lawns into woodlands or gardens, and using integrated pest management rather than reaching for a chemical solution. We need to do more to enhance food safety and food security for ourselves and future generations.

Attracting beneficial insects

In order to see more butterflies in your garden and to ensure good (bee) pollination for your vegetables, plant natives and use integrated pest management. This printable PDF provides tips for attracting beneficial insects.

Swallowtail caterpillar on Echinacea purpurea