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.