• What to do about poison ivy?

    Question

    A large willow tree in our yard was damaged by a wind/snow storm and was taken down. We stopped removal when we found large areas of poison ivy. What is the best nontoxic removal of poison ivy on a large area?

    Naturalist's Response

    Poison ivy leaf

    Oooh, this is a tricky one:

    It’s very difficult to eradicate a thriving growth of poison ivy, and it’s even harder to do so without feeling the plant’s itchy effects!

    Protecting Yourself From Itching:

    You will have to wear gloves and thoroughly wash up, as well as thoroughly wash any tools and clothing that you wore while working with the poison ivy in your yard. The oil from the plant, which is what causes the rash, can be spread from the tools onto your skin, and can remain on the tools until it is washed off.

    There are specific products that you can use to wash yourself both before and after to help prevent the rash, should you wish to research those online.

    Removing The Plants:

    Poison ivy, Toxicodendron radicans, is a hardy plant, but it can be killed with most systemic herbicides.

    Most commercially produced herbicides that target poison ivy are based on the chemicals glyphosate, 2,4-D, or triclopyr.  (I’ve included links for each to the handy reference sheets from the National Pesticide Information Center.)

    There are alternatives that offer less risk of harm to yourself and the environment, but which still kill plants:

    • Horticultural vinegar:  Vinegar (acetic acid) works well as a plant-killing spray.  Household vinegar is typically diluted to 5% acidity, but you can find ‘horticultural vinegar’ with a strength of 30% acidity at lots of hardware and garden stores.  Adding some dish soap (about 1 ounce per gallon of vinegar) as a surfactant will boost its efficacy.  There are also commercially-produced, vinegar-based weed killers with the soap already mixed in; again, check your neighborhood store.
    • Citric acid:  Similarly to vinegar, citric acid is a food-safe ingredient that’s been incorporated into several commercially-produced weed killers.  (It’s often combined with clove oil for an extra punch.  Bonus: it makes your garden smell like a spice rack!)  Try a web search for “citric acid weed killer” and you’ll see plenty of examples.  I’ve found that more and more Ohio stores are carrying these products nowadays in an effort to carry a ‘more-natural’ inventory.
    • Boiling water:  Some gardeners swear by using boiling water to kill poison ivy plants at the root.  Just be sure to use all the safety measures you’d use in the kitchen; nobody wants to stand in a cloud of poison-ivy-infused steam!

    Unfortunately, it usually takes a lot of work to conquer an established patch of poison ivy. Whether you pull, dig, cut or spray, it will likely take several rounds before you knock out your opponent. (That’s why we think poison ivy would make a great mascot for toughness and resilience!)

    Best of luck!

    -Naturalists Denise Wolfe & Chris Mentrek