On rubbing up against poison ivy


You’ve probably seen the reports of bumper crops of poison ivy these days, thanks to global warming. (Here’s one on National Geo).  And last week Anne Raver wrote in the NY Times about a horticulturist cashing in on the problem.  He’s Umar Mycka, a career horticulturist at the Philadelphia Zoo (the largest public garden in the area, he tells us) and he started a business called Poison Ivy Horticulturist. Homeowners too allergic to remove the toxic weed themselves (or too busy, you know) pay Umar to don his hazmat suit and do the dirty deed for them.

So Umar, I have a question for you, coz I’m seeing more of it in my garden than any year since I removed it all – as of that moment in time.  Birds WILL crap while flying over our gardens, so poison ivy is never gone for good.  So here’s the question: When I think I’ve rubbed up against some, I should run into the house and do what? 

Raver mentions that there’s conflicting advice on this score and recommends her own favorite tactic – “jewelweed, a soft, green-leafed plant with
little orange flowers that often grows next to poison ivy in damp areas, near streams.”  Its stems and leaves should be crushed and rubbed on the PI sap.  And guess what – Umar uses it himself and keeps it handy in ice cubes form.  Well, that’s interesting but what’s a
jewelweed-less gardener to do?  Let’s consult the handy links on Umar’s site.

From Ohio State:If contacted, affected areas should be washed immediately with soap and water as well as any clothing or objects that may have come in contact with the oil. This activity will not decrease the severity of the reaction, but it will lessen the chance of spread.”  Oh, that’s encouraging.

Referring to both poison ivy and oak, his California source writes:  “After coming in contact with the allergen, the best way to prevent skin irritation is to pour a mild solvent, such as isopropyl alcohol (rubbing  alcohol) over the exposed area and then follow this with plenty of cold water (warm water enhances penetration of the oil) within a few minutes of exposure. If isopropyl alcohol is not available, just wash with lots of cold water. But you need to wash within 5 minutes of exposure to prevent a rash. Even if it is too late to prevent the rash, washing the skin to remove excess plant oil will keep the rash from spreading.

“Using only a small amount of water or disposable hand wipes is more likely to spread the toxin than remove it.  Soaps can be used to wash, but only if used with copious amounts of water; otherwise, they too will spread the toxin.

“If a rash develops after exposure to poison oak, the use of a product called Tecnu, which is sold at most drug stores, will relieve the itch and reduce the rash. When applied once a day, it stops the itching for most of the day and clears up the rash in about 7 days.”

Thank you, UC Davis!  This information is so complete that I want to kiss those hort geeks.  Not for them the usual tepid, CYA nonanswers given by so many academic sources.  They also confirmed what I’d read long ago, that sensitivity to poison ivy increases with each exposure, so don’t anybody assume you’re immune because the next run-in with it could change all that. 

My new best friends at UC Davis also confirm that glyphosate is the most effective herbicide against it, but only if you use it late in its growth cycle, presumably late summer.  Omar uses an herbicide called Vine-X, and here’s what Raver says about that: “It is not clear how toxic it might be to mammals, fish or ducks so I, for one, would
rather just pull up the weed.”  Well, wouldn’t we all.  And when that’s not possible?

That’s when dispassionate research-based findings from fat public universities really come in handy.



  1. How about: grow Jewelweed? It’s a pretty native wildflower, with both yellow and orange forms. There is not a child on the planet who can resist popping its seed pods (and few adults!).

    It’s a nice addition to the garden…:)

  2. I am allergic to poison ivy and have successfully used Dawn dish washing detergent to remove the ivy oil. As long as I wash up with cool water and Dawn within an hour of exposure, I have not developed a rash. Dawn is one of the best grease cutting detergents on the market so it seems reasonable that it could do a good job at removing the ivy oil. I heard about Dawn through my friend who had fallen into a patch of ivy (pulled by her dog), washed with Dawn 1.5 hours later and did not develop a rash. That convinced me to try it.

  3. Ironically (in this poison ivy context) jewelweed is sometimes called Touch Me Not because, when touched, the seed heads explode and scatter in all directions.

  4. Anne Raver is probably referring to the active ingredient in Vine-X. She probably has not seen the product. It is a terrific product for killing hard to kill woody weeds. It is safe for all of Anne’s worries because it comes in a container with a small applicator brush on the top. The material comes out only thru the brush which makes it very easy to get the stuff only on the plant to be dispatched. What’s really neat is the weed dies when only six or eight inches of the base of the stem are brushed with the herbicide. It also works in the winter. Unfortunately the guy who makes Vine-X is in financial trouble and may already be out of business. Here is a totally wonderful safe tool for all homeowners and he couldn’t get it to a national market.

  5. Tecnu makes a wash you use within a few hours of exposure to remove the toxic oils. It will usually prevent the rash altogether. You can even use it after the rash develops if the skin hasn’t become too raw and blistered. I always keep a bottle of Tecnu on the shelf.

  6. To eradicate it, I think the method some friends used to get rid of their kudzu will work. They cut the vines back, leaving approximately a foot out of the ground. Then they got empty soda cans and filled them with liquid Round-up, and put the vine ends into the cans, checking every day or so to refill as necessary. The vines sucked the herbicide through the roots, and they never had kudzu again. Maybe that will work with the poison ivy.

  7. Naomi, I’ve found Round-Up works pretty well on Poison Ivy when just carefully sprayed on, but I’ll sure keep this method in mind if Kudzu makes its way up here!

    It’s found in a few patches in Illinois, and probably will spread North over the next few years. It’s already been found as far north as Peoria.

  8. Thanks. They lived in the last townhouse of 10, with a hillside behind the homes. It was very odd to see their daylilies, irises and hostas, while all the other homes had only kudzu – this 3 years after they’d cleared it out. And Round-up is supposed to dissipate after a short period, which seemed to be true at their house.

  9. Let me second the effectiveness of vine-X — the active ingredient is triclopyr which you can buy in many other herbicides — but that brush is really handy and environmentally smart (keeps the herbicide where it belongs). I haven’t seen it in stores this year — though I did last year — I hope it’s not gone.

  10. Active ingredient in Vine X is tryclopyr………..the same in Ortho Brush B Gon. However the chemical formulation is a different “esther” or “salt” so I was told by Vine-x

    Vine-X shoule be relatively harmless since it is a topical application brushed directly on to the base of the stem or trunk of poison ivy instead pf sprayed on like glyphosphate (Round Up)

    It is used in it’s concentrated form not diluted. It then permeates through the bark and is systemicly translocated to the root.

    The idea here is to use less product in less of a coverage area reducing overspray, wind drift etc.

    The (esther of a diffrent sort) TROLL

  11. Just be aware that poison oak/ivy rashes can not show until 2 weeks after exposure. That’s what happened to me–I was out on maneuvers in Northern California, crashed and fell through more brush than I care to remember. Two weeks later, this red, itchy rash (red bumps) showed up all over my shins, and ONLY all over my shins. I’d worn the same fatigues at least twice since I’d worn them on maneuvers, and they had been thoroughly washed several times, once immediately after said maneuvers. I went to a typical Army doctor, who told me it was “just mosquito bites”. Two days later, when the “mosquito bites” started running, oozing and getting worse, I went back. At that point he brilliantly deduced it was poison oak, and gave me steroids to speed the healing. Unfortunately, the rash left my shins looking horribly bruised. On my next visit for some other injury requiring medical attention, the doc noticed the bruising, and started interrogating me about my love life: was I being beaten by my boyfriend/spouse? He didn’t believe it was just the residual from the poison oak, but he finally just dropped the subject.

    Anyways…I hadn’t had any direct contact with poison oak on exposed skin except my face and hands, and they NEVER showed any rash. My shins had been protected by knee socks, knee pads. combat boots and fatigue pants (which had a double layer of fabric over the shins). Go figure.

    I now live in a poison oak/poison ivy/cat and dog flea/chigger free area. Okay, so I live in a desert, but…

  12. I just found out about Tecnu and bought some at Walgreens to try the next time I come in contact with poison ivy.

    We have more than ever here this year – we have had 40-inches of rain already for 2008 making the growing conditions perfect for everything the birds deposit.

    The Dawn idea sounds easy to try. Thanks for the tip.

  13. This year was my first time to be affected by the dreaded poison ivy.I still dont know where I got it.Thought the red bumps were Bites.When the itching and blistering made me think otherwise it was fullblown.The Doctor subscribed the usual Pills and Creams but the thing that really gave instant relief whenever applied was simple Handsanitizer.It burns for a second,then there is itch relief.Since it is Alcohol based it also helps to dry out the spots

  14. Tecnu is the BEST! I used to have a bout or two of poison ivy every summer until I found this stuff. Now if I think I touched any of the plant I immediately wash the affected area with tecnu using, and here is an important detail, the hottest water I can stand. When I do this I never get the rash.

  15. Grouchylisa, what happened to you was that your skin was exposed to a small amount of urushiol and you had a delayed reaction to it. When exposed to a larger amount, the reaction is fairly quick.

    We also swear by Technu. It’s an amazing product. I also use Ivy Block to treat my face before I pull up the stuff. I wear a painter’s mask, goggles, painters coveralls and rubber gloves over garden gloves for the job.

  16. For the first time in my life, I got the poison ivy rash this year. After scrubbing, steroids and much itching, I still have some of it hanging about. I can’t get it to go away completely. The depths of misery for poison ivy sufferers is unmatched in my opinion.~~Dee

  17. I got only a touch of it this year, luckily (I was anxious when it appeared on my face several weeks before my wedding!) but the cure I learned of last year (after three years running of worse and worse outbreaks on my arms, legs and torso) works a charm for me: apply very hot water, as hot as you can stand, to the affected area. Best to start with hot and work up to very hot under the faucet. It will be excruciating for a moment. But then, the itch will subside for hours, and the rash will clear up a lot quicker than it normally would.


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