Poison ivy can leave behind a lingering problem in your garden

When you’re finished, don’t touch your door. Don't touch anything.

By Jessica Damiano | The Associated Press

For all the time I spend digging, planting, pulling and weeding, one would think I’d have some poison ivy horror stories to tell, but I do not. I can’t say for sure whether I’m immune to the rash that tortures so many of my fellow gardeners or if I’ve just been lucky, but one thing is for sure: The plant does pose a serious problem for many who come into contact with it.

Botanically known as Toxicodendron radicans, poison ivy contains oily chemical compounds called urushiols in its leaves, stems and roots. According to the American Skin Association, about 85 percent of the U.S. population is allergic to urushiols, with roughly 10 to 15 percent of those considered “highly allergic.”

That makes the plant concerning — and possibly dangerous — for most Americans, with 50 million people affected each year, the group says. So, in most cases, it should be removed.

But the itchy, blistering and sometimes painful dermatitis that affects most people who brush up against poison ivy can discourage efforts to tackle it.

It’s a Catch-22: You need to remove it because you’re allergic but you’re allergic so you can’t remove it.

First, know how to identify it.

Making a positive ID can be tricky.

Poison ivy takes on different appearances at different times of year. Most often, its leaves are composed of three leaflets apiece (as referenced in the childhood rhyme, “leaves of three, let it be”). The middle stem is longer than the stems of the side leaflets. Young foliage is shiny; older leaves are dull. Larger, older vines, especially those climbing up trees, are hairy. Leaf color can be green, red, pink-tinged, yellow or orange. Leaf shape can also vary, with smooth, lobed or toothed margins.

I’ll confess, it confuses me, too. I once pulled up a raspberry plant (R.I.P.) that I misidentified as poison ivy.

Consult with a poison ivy expert, bring a (bagged) sample to your local cooperative extension office, download a plant identification app or compare photos of your vine to those in books or on an educational website.

Then, either call in a professional or, if removing it yourself, carefully implement protective measures.

How to remove it safely

Wear long sleeves, pants, gloves and goggles, and don’t touch anything, especially your face, during the process. Avoid contact with tools or clothing used during the job, and remove all clothing afterward so as not to allow it to come into contact with skin or other surfaces.

The best way to eradicate poison ivy is to pull it up by its roots. If you garden in a four-season area, the job will be easiest in early spring, after winter’s freeze-thaw cycles have softened the ground. Otherwise, waiting until after rainfall is best for the same reason.

Pulling, you’ll notice, will likely leave some of the roots behind, as they can grow up to a foot deep. The entire root system must be completely dug up to avoid a reoccurrence, but if you’re tired, that can wait until tomorrow.

As you dig, you’ll notice the plant also has runner roots that have grown horizontally under the soil surface. Depending on the size of the plant, they can extend up to 20 feet from it. Remove them, too.

How to clean up properly afterward

Proper disposal of all plant parts is critical. Place them in a tightly sealed, heavy black plastic bag and set it out with the trash. Never burn poison ivy, because the smoke would contain toxins that could be fatal if inhaled.

When you’re finished, don’t touch your door. Don’t get yourself a drink. Don’t open the washing machine. Don’t. Touch. Anything.

This is easiest if you have someone to open the door, put your clothes into the washer, etc. If not, take care to do things in the proper order to avoid cross-contamination: Strip naked, remove your gloves then wash your hands with a liquid cleanser specially formulated to remove traces of the resins. One is Tecnu, which also can be used to launder contaminated clothing.

Then, bring the bottle into the shower with you. Avoid bathing with ordinary soap because it can spread the oils to other parts of your body.

Urushiols can also be transmitted to people via gardening tools, footwear, clothing and pets for as long as a year or two after contact, so anything that touched the plant should be thoroughly cleaned, too. Then wash your hands again. You can’t be too careful.

As time goes on, some sprouts will likely reappear, so repeated pulling and digging may be required over the next several seasons.

Other options

If pulling is not possible, herbicides containing triclopyr or glyphosate can be used to kill the plant. I do not advocate the use of these chemicals except in extreme circumstances, such as to control Japanese knotweed. But if you are severely allergic, I consider poison ivy removal in that category.

Just know that these herbicides will kill every plant they come in contact with, including grass. They also have toxic properties that will remain in the soil for some time. Use them only on a windless day to avoid overspray and take care to directly target only the poison ivy. Apply to leaves as directed, following precautions on the package label.

Plants should wilt within 24 hours, turn brown within three days and die in a couple of weeks, at which point they can be removed. Take the same precautions as above because dead (and dormant) plants still contain toxins. Repeat applications may be necessary.

And don’t get cocky. Just because you’re not allergic today doesn’t mean you won’t be tomorrow. Always protect yourself.