About Poison Ivy

Poison ivy, Toxicodendron radicans, is native to eastern North America from Canada to Florida, and as far west as Arizona, occurring naturally in fields, woodlots and fencerows. Plants form a sweeping ground cover up to two feet tall, and at the first opportunity, begin to climb by clinging to tree bark, buildings or posts.

All parts of the plants are laced with urushiol oil, a potent substance that causes the rash that instantly comes to mind when we think of poison ivy. The oil is sneaky. We brush against the leaves, pull a few as weeds and feel no sting or irritation. The urushiol binds to skin within 10-15 minutes of exposure, and over the course of hours, days or even a week two, our system kicks in with the classic itchy, weeping rash.

If we realize that we’ve been exposed, we can rush to wash thoroughly to remove the oil before it soaks in. Other times, we are completely unaware. Many times the family pet is the vector, returning from a romp in the backyard with just enough urushiol on their fur to cause a reaction to the owner who later pets them.

About 10 or 15% of the population is not sensitive to the oil and will never have a reaction. But if you’ve never had poison ivy, don’t be too quick to assume you are immune. It all depends on how much exposure you may have had over the years—everyone has a different threshold, and it is difficult to know how much direct contact you may have had.

It seems that only humans are sensitive to urushiol. Wildlife and pets can coexist without a reaction. Birds enjoy the plant’s white berries, and grazing animals eat the nutritious foliage with no ill effects.

Poison ivy is a tough plant, with deep roots and reserves. Even specially formulated herbicides labeled for poison ivy usually require multiple applications to completely kill the plants. To add insult to injury, the dead stems and leaves are just as full of the toxic urushiol as when lush and green—and this includes the top growth that dies back in the fall—there is no ‘safe’ season to handle these plants. The roots are loaded too, so beware if you try to dig them up. And don’t even think about burning it, dead or alive. Breathing the resulting smoke, soot and ash can result in a horrible reaction.

So, what to do?

If I spot a seedling or small plant in the garden, I put on disposable vinyl gloves and slip a plastic grocery bag over one. Grasp the plant firmly at its base and pull up with the roots, then carefully pull the bag back over my hand to wrap the ivy.

Recently, however, we discovered an enormous patch in our field while mowing a walking path. We weighed the options, and finally settled on an unconventional solution.

Goats.

We procured a portable electric fence and a pair of discount goats—older animals that had little to offer beside their appetite. They are happy to browse with no supplemental feeding, and have been at work since early July, eating poison ivy, goldenrod and any pasture grass within their reach.

So far, so good.

Even eaten to the ground, the ivy will resprout—but the bulk of the top growth will be gone, and any returning growth can be hit with herbicide without leaving a lot of dead mass to deal with.

We’re hoping this approach will control, if not eliminate the ivy problem. I’ll keep you posted.