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.

How to have happy houseplants

Do you have a houseplant that seems unhappy? Trust your gut. If the plant looks like it’s struggling, it probably is. But don’t worry! There are only two causes for most indoor plant problems: light or water (or both). And I’m going to let you in on the top-secret two-step method for houseplant happiness.

All too often, houseplants don’t get enough light, or they drown in too much water, or they dry out because we forget to water them. It happens. It doesn’t make you a bad person.

Want to learn more about houseplant care? Here are some of my favorite online resources:

Oh no! Looks like it’s too late for Mr. Crispy.

Here’s the top-secret two-step:
1. Look at your plant. Does it look happy? Does it look strong and proud or weepy or saggy or sparse or shriveled? What color are the leaves? Look at the soil. Is the surface smooth, cracked, covered in white crumbs or green goop? Touch the soil, heck stick your finger in the soil at least to your first knuckle. Is the soil dry and brittle? Dense and soggy? Gather up your data and visit the links above.
2. Do something different immediately, but not too different. Yes, your struggling plant needs a change, but too much change at once could kill it. Change your watering frequency or move the plant to a new spot or repot the plant. Doing all three at once could be too much stress for an already struggling plant.

My houseplant care regimen looks like this:
1. Bring plants indoors when nighttime temps get to 50 degrees and below. Place them near windows that best approximate their light needs. Some of the plants overwinter under grow bulbs.
2. Water the plants every week unless they don’t need it (finger into the soil to test). Take the plants to the sink or the shower, water thoroughly, let them drain, take them back. I often rotate the plants so a different side faces the window every week, to keep the growth more consistent. I rarely fertilize houseplants in the winter.
3. Take most of the houseplants outdoors when nighttime temps get to 50 degrees and above. Keep them in the shade (I like to hang them in trees) or with at most a few hours of morning sunlight.
4. Water when they need it, paying attention to how often it rains or just use the aforementioned finger test. If it’s hot and it doesn’t rain they need water multiple times per week.
5. Fertilize once per month. I’m a big fan of Planet Natural‘s organic fertilizers.

All else equal:
Plants in bigger pots are more resilient than those in smaller pots.
Plants in pots with drainage holes are healthier than those in pots without holes.
Squishy-leaved plants (succulents) need less water than other plants.
Flowering plants need more water than other plants.

I hope the links above will help keep you and your houseplants happy together. But if you need some more help, let us know.

Happy houseplants

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 food.

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.

Gardener’s to do list for late spring

This post originally appeared in the Penn State Extension Master Gardener’s blog.

All vegetable gardeners want a successful harvest, and I’ve found that no time is more pivotal than the first month or so after planting. This is when our seedlings take root, and establish a strong foundation for future growth. I spend more time in my garden in spring than any other time of year, and it always pays off. Here’s a list of late spring tasks that will benefit your organic vegetable crops.

Monarch caterpillar feeding on milkweed leaf

1. Attract Pollinators

Many of our vegetable plants already attract bees and butterflies, but we can supplement these with flowers like Echinacea, bee balm (Monarda), zinnias, yarrow, and sunflowers, among others.  I like to grow common milkweed (Asclepias syriaca) to attract Monarch butterflies, and bronze fennel to attract Swallowtails. It’s also a good idea to include a shallow water source for the pollinators. You’ll find some more tips in my printable PDF. And if you’re committed to attracting pollinators, you could get your garden certified.

2. Protect your vegetables from critters

I live in central city Philadelphia, but my vegetable garden lives in rural Berks county (zone 6b). I see no deer or groundhogs in my Philly neighborhood, but they certainly frequent the neighborhood around my garden. The local rabbits are quite voracious as well. So I’ve installed simple 8-foot long 2×4 posts (not pressure-treated) and plastic deer fencing. I added some short galvanized wire fencing to keep the rabbits and groundhogs from gnawing through the deer fence. I’ll have to keep an eye on my fence throughout the growing season, because those critters are crafty, and just might find/dig/gnaw a way through or around my fence. Vigilance is key.

munched tomato
Somebody got to my tomato before I did.

3. Weed and mulch

As they establish themselves, our vegetable plants compete with weeds for sun and water and soil nutrients. My garden is host to a seemingly endless army of thistles and wild onions. Until my vegetables are large enough to shade competitors, I need to weed frequently. I also use mulch to keep the soil moist and discourage weeds. Some gardeners use inorganic materials, but I prefer organic mulch. It doesn’t keep every weed out, but it will slowly decompose and further nourish my soil.

You might consider red plastic mulch for your tomatoes. Penn State scientists found that red mulch increased tomato harvest by 10 percent on average.  To keep the weeds at bay and encourage a better tomato harvest, staple red mulch to black mulch  and lay it on the ground red side up. The easiest time to do this is before you plant your seedlings, but you could also lay it after planting, and create cut-outs for your tomatoes to poke through.

4. Erect plant supports

If you haven’t yet done so, now is a great time to install plant supports.  Putting off this task will leave you wrestling with large plants, and you’ll risk breaking the stems and damaging the roots. Supports are particularly important for peas, pole beans, and tomatoes. I also like to provide supports for my cucumbers, and occasionally for my pepper plants. Garden supply stores offer a wide variety of stakes, teepees, and cages, but you can also make your own. In order to keep your garden chemical-free with natural materials, choose bamboo, cedar, cypress, and jute twine. I use jute twine throughout my garden, because I can toss it in my compost pile in the fall.

Cucumber seedlings starting to climb

5. Make frequent inspections

Organic vegetable gardening is actually really easy. The biggest time commitment comes in the spring, but the summer and fall payoff is truly worth it. Take a little extra time now to nurture the plants and help them set a strong foundation. The absolute best thing you can do for your garden now and throughout the growing season is to walk around and look at the plants. How are they doing? Are they getting enough sun and water? Do you see any evidence of disease or insect damage? Catch it early, and your plants are likely to recover.

I love composting

I love composting.  I mean I really love composting.  Every part of the composting process makes me so deeply happy, it’s probably strange to most people.  I find composting satisfying on so many levels.  I don’t put out all sorts of yard waste, I don’t toss my food scraps in the trash, and I don’t dump all kinds of crap in the garbage disposal.  And then, I get this amazing, sweet smelling happy soil amendment for my plants.

One of my earliest low-low-tech composting systems

But I understand that it isn’t easy or obvious for everybody, so…I’ll dive into some tips.

One of my facebook friends told me she has trouble with her tumbler.  Tumblers work best when there’s a good moist (like a wrung-out sponge) mix of “greens” and “browns” that is left alone (nothing new added) for a while, and tumbled from time to time.  If you keep adding ingredients to your tumbler, you won’t get good compost, because you’d have to sift out the newer ingredients.  A tumbler with only one compartment isn’t enough for an effective year-round compost operation.  Some tumblers have two compartments, so one is for adding and the other is for compost-cooking.

The mix of greens and browns isn’t an exact science, though a number of books and web pages suggest a certain mix of each.  In my personal garden I ignore that, because composting as waste disposal is only useful to me if I can add whatever I have when I have it.  “Greens” are mostly green, but this also includes your food waste.  If you only put food waste (and no yard waste) into your tumbler, it’s too green. It won’t decompose well, and will probably smell funny.  Add browns, like dried leaves, dried grass clippings, or shredded soy-ink newspaper scraps to the mix.  And make sure it isn’t too dry, it should be just damp (not soggy) for best cooking.

As with most horticulture, the best way to maintain compost bins is by looking at them from time to time.  Does the compost stink?  Add browns.  Is it too dry?  Add water.  It is moist, not stinky, but still not decomposing?  Well, it’s either winter or you need more greens.

I heartily welcome any and all questions about composting. How’s your compost bin cooking?

Starting garden seeds indoors

It can be a challenge to find good information about what plants need and when it’s safe to plant them outside. This printable table provides sunlight and soil depth requirements, along with the earliest dates to start or transplant these vegetables and berries outside. This information applies to gardens in the Philadelphia metro area, which is USDA hardiness zone 7. The soil depth requirements also assume you are growing varieties that are suitable to container growing.

You can start plants anytime after the dates shown. If you choose to start early, make sure you watch the weather, and gently cover your plants if it gets “cold” again. For annual vegetable plants, “cold” generally means mid-thirties or lower. You could also watch weather forecasts for frost or freeze warnings. It’s also important to remember that the conditions that damage tender plants are determined not only by air temperature, but also by soil temperature, moisture, wind, and precipitation.

Determining the “last frost date” is not an exact science. Current estimates of the last frost date for Philadelphia range from April 6 through April 30. At EFTE, we have scheduled seed starting according to a last frost between April 15 and April 22.

If you are a relatively new gardener, it’s safer to err on the side of caution, and plant your garden later rather than sooner. If your plants are in the ground too soon, they might survive the conditions, but they won’t be as productive as they would otherwise.

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