How to Identify Poison Ivy

If you know me or have been reading my blog for awhile, you know that I haven't always been such a nut about nature, birds, and gardening. In fact, it was only about five or six years ago that I started to get outside again, after twenty years in an office. It was during my first year as an outdoors woman that I learned about that evil invasive English Ivy and the evil itch of Poison Ivy.

Since I live in an older neighborhood just 3 miles from Colonial Williamsburg, colonial-type architecture, big hardwood trees, and tradition plantings dominate. English Ivy has run amok. Without the homes and lawns, my natural community would be a mesic mixed hardwood forest, which seems to reappear in the second-growth strips between houses in older subdivisions like mine. Sometimes I wonder if the root stock in my yard was brought by the colonists, perhaps Mark Catesby himself. Actually, that's not such a far out thought because English Ivy is a native European plant that was introduce to North America during colonial times. It was a traditional (you know, as in "The Holly and The Ivy") ground cover that grows fast in sun or shade and is drought tolerant. And it out-competes other plants. In my yard, several English Ivy vines as big around as my arm have out-competed several small trees, may they rest in peace.

So, when I decided to care about my yard, job one was to set to work pulling Ivy. It's the only way to get rid of it, so I've been told. There are some versions of Roundup for woody vines, but I didn't want to kill the native American Euonymus or any American Holly or Flowering Dogwood saplings, or any other native inhabitants of my mixed hardwood forest. One August weekend, I spent a whole weekend pulling Ivy into a huge pile for the garbage man and then we went on vacation. And I started itching. Poison Ivy. Miserable vacation. Miserable homecoming. Miserable month until the stuff was gone. I can still see scars where I popped a couple of the blisters. That's a no-no.

These days I can definitely identify Poison Ivy. There are several sing-song-sayings to help you too, such as "leaves of three, let it be," "berries of white, run in fright," and "hairy rope, don't be a dope." (See the photo here of a vine at New Quarter. Yipes!) One time I was out with a Boy Scout Den at New Quarter Park and I was warning the boys about poison ivy. One of them said that the leaves look like a mitten. Great observation.

Poison Ivy is native to Virginia. It has waxy leaves with a serrated edge (think steak knife edge) that grow in groups of three leaflets.The two outside leaflets look like mittens. The center leaflet looks like a two-thumb mitten! In the summer, small green fruits slowly grow round, ripe, and white. The berries are noxious for people too, but birds love to eat them in autumn.

Since my yard is a wildlife habitat, I don't pull every piece I see. When it's in an out-of-the-way place, I leave it alone. When I do decide to pull a bit of it to keep it in check, I put my arms in those long plastic bags that the newspaper comes in to pull up the vines. I carefully pick up the ivy that I've pulled and pull the bag off my arm, inside out, so that in the end it contains the ivy, which I put in the garbage.

The element in Poison Ivy called urushiol is what causes an allergic reaction in humans. The skin becomes itchy, red, and blistered. It is not pretty. Urushiol is on the leaves and the vines and roots, so it's not safe to touch any of the plant. Don't mow it or burn it either, because the urushiol becomes airborne and can be inhaled. That can be life-threatening.

The Urban Jungle column in last Sunday's Washington Post mentioned a lot of this same information and also included a sidebar about global warming and Poison Ivy. Here's what they had to say:

Global warming, poison ivy swarming

Poison ivy responds robustly to increasing CO2 levels, stepping up leaf and stem production -- even increasing its concentration of urushiol.

Scientists grew identical sets of poison ivy plants in atmospheres with various concentrations of carbon dioxide, based on levels from the mid-20th century, the present day and a projected future. Two-inch rhizome segments were sprouted and cultivated for 250 days before leaves were harvested and measured. 


I've noticed that we had an awful lot more poison ivy at the park last year, but like everything else, the heat may have stunted it's growth this year. In any case: Poison Ivy: It's One More Thing To Worry About! Geez, Louise.