Anti-Vine of the Month-Poison Ivy
The only reason I put this plant in the “Anti” category is the annoying rash and blistering it causes, which can be a nightmare worse than Nightmare on Elm Street and last longer than a week-long binge of Friday the 13th sequels. (Fun fact: according to Google, there are twelve Friday the 13th and nine Nightmare on Elm Street movies! So far…)
Like the start of most Halloween slasher movie plots, Poison ivy, Toxicodendron radicans (syn. Rhus radicans), starts beautiful and peaceful…the plant is a Missouri native with many ecological benefits such as the many songbirds that feed on the white, waxy berries, especially during fall migration and in winter when other foods are scarce. Deer and small mammals also feed on the berries as well as the foliage and stems.
Aesthetically speaking, the berries are attractive. As a close relative of our native Virginia creeper and sumacs, it can be quite stunning with its brilliant red fall color.
Poison ivy (PI) can be quite adaptable, preferring somewhat moist soils in sun or shade, but it can grow in many soil types and is quite drought-resistant. It can soar to 60’ in mature trees or along walls and fences. It can be a small, tender vine when young, and mature into a thick-stemmed vine or shrub-like mass. Because songbirds love the berries, one of the most common places to find it in residential areas is under trees or shrubs and along fences, where birds frequently sit and, well, take care of business, depositing the newly stratified seeds thanks to their digestive system. Like many of our worst invasives, this is a sneaky way to establish, out of sight of even the most seasoned gardener, unsuspecting homeowner, small child, or family pet.
Cue the creepy music…here is where the plot turns and you realize the nightmare is about to begin…BRAAHAAHA! Resinous sap found in the leaves, stems, and roots of PI contains components known as alkylcatechols, collectively called urushiol (pronounced oo-roo-shee-ohl). Touching any part of the plant can transfer it to your skin, but many people don’t realize that if your dog or cat brushes by PI and gets the oil on its fur, you can get an itchy rash by touching your pet. The same goes for your shoes, clothing, and even your gardening tools. Sounds super scary, right? But wait, it gets worse! (The music grows scarier and faster!) If an unsuspecting homeowner burns poison ivy with their leaves, or you attend a Halloween night bonfire where the wood was covered in poison ivy vines, the oil can be transported directly to your LUNGS and cause a life-threatening medical emergency. Call 911 if you or someone else experience any of the following symptoms;
- Difficulty breathing, wheezing, or shortness of breath
- Severe, painful coughing or throat tightness
- Swelling of the lips, tongue, or throat (angioedema)
- Dizziness, nausea, vomiting, or high fever
I hear those of you out there saying, “Well, I don’t get poison ivy.” Famous last words…like the doubters that are the first victims to get killed off in Halloween II. It’s true, some people are more sensitive than others to the oil, but the allergic reactions seldom occur on the first exposure; they increase with each exposure. About 70 to 85 percent of the population will develop an allergic reaction to poison ivy, poison oak, or poison sumac.
There’s that creepy music again. What’s even weirder, your sensitivity can change. Repeated exposure may make you more sensitive, so you react to lower and lower concentrations. The good news is many people become less sensitive to urushiol oil as they get older.
So, how do you prevent poison ivy from growing in your garden or yard? You can’t. Just like the poor, supporting teen actors in those slasher films that get killed off first, PI will happen sooner or later. HOWEVER, the main characters in slasher movies do three things to make it to the end alive: educate, protect, and prepare for battle.
1. First things first. Learn how to ID poison ivy. Remember the saying, “Leaves of three, let it be!” This is your chant for warding off evil. Not all plants with three leaflets are poisonous, but unless you are 100% sure, don’t risk it. Be like the Beatles and LET IT BE!
-Poison ivy leaves consist of three “leaflets” that are arranged alternately along the stems. (Other similar-looking plants like box elder have leaves arranged oppositely along the stems) Virginia creeper, when young, can also have three leaflets arranged alternately, but follow the vine closer to the roots and you’ll eventually find five leaflets. Fragrant sumac leaves also resemble PI; check it out here; (LINK)
-Poison ivy leaves usually have serrations or pointy lobes, but not always.
-Sometimes on older plants there are tell-tale black spots on damaged leaves caused by the oxidation of the urushiol oil.
-When it climbs a wall or tree, poison ivy stems have fine aerial rootlets that cling as they climb.
Keeping an eye open as you enjoy and work in your garden or yard is key to catching PI before it gets out of hand! Once you’ve identified it, you can move on to the next steps.
2. Protection-There is a product called IVY BLOCK (bentoquatam) that can be applied up to 10 minutes before exposure, but a physical barrier is always recommended. Any encounter with PI requires head-to-toe protection, with a healthy amount of awareness. I recommend shoes you can throw in the washer or hose off afterward, pants, socks that extend past your pant hem, long sleeves, and a hat. If you have long hair, tie it up under your hat or twist it in a bun. Top things off with rubber gloves that extend past your wrists and sleeve cuffs. Cloth gloves are asking for trouble. You don’t want the oils to seep through the material to your skin.
3. Prepare for battle. For small plants under 24”, I take two plastic bags and cover both my already gloved hands past the wrists like a second glove. Grab near the base of the PI and pull the entire plant out by the roots. While still holding the plant, peel the plastic bags down over it, tie it up, and deposit it in your TRASH bin, not your yard waste bin. For slightly larger plants, you can use trash bags in the same manner. NEVER put PI, dead or alive, in your compost or yard recycling bins.
-For larger vines like on trees or walls, the cut and paint method can be used. Make two cuts near the base of the stem about 2” apart and remove the 2” piece. Apply herbicide directly to the bottom cut stem to kill the roots. Doing this in fall is more successful than in spring. The top part of the vine will eventually die, but keep in mind the leaves and stems still contain toxic oils that can cause a reaction. Like a zombie, PI can harm you even if dead! BE AWARE: If you leave the stems attached to the tree, PI leaves will mingle with regular tree leaves when you rake them up.
-BEWARE! Please be aware that if you sneeze, have an itch, swat a mosquito, need to wipe sweat running into your eyes…do NOT touch your face or any other exposed parts of your body!
-Afterward, peel off any exposed clothing carefully to avoid touching your face, neck, wrists, or hands, etc. Turn the clothes inside out and wash immediately to avoid spreading the oils to your hamper or clothes basket. Hose off your shoes, taking care not to splash any oil-mixed water back onto yourself. I wash my hands immediately after putting my work shoes on or off, just as a precaution. PI is as sneaky as Jason at Crystal Lake; sometimes you don’t know that you’ve stepped on or through PI until it’s too late.
-Clean the skin with large amounts of isopropyl (rubbing) alcohol within 10 minutes if you want to be extra cautious, then wash with cold water (without soap). Using soap alone can lift the urushiol oil and spread it to other parts of your body.
-Wash or wipe your tools afterward with rubbing alcohol, especially the handles.
Some soaps claim to wash off the oils, but you must use them within 30 minutes of exposure.
If you are exposed, signs can appear within 12 to 48 hours. The rash, itching, and blisters will disappear in 14 to 20 days without treatment, but hydrocortisone can help relieve the itching. For severe cases, see your doctor who may prescribe an oral corticosteroid.
We can’t eliminate PI, but with a little awareness and persistence, you can prevent an itchy, blistering sequel of the exposure nightmare!
-Comments or questions? Email Garden-Lou at gardenloustl@gmail.com
Words and photos by Jo Batzer
© Jo Batzer, garden-lou.com-2026, All rights reserved.
