Farmers Weekly Review

Poison Ivy in fall and winter takes on a whole new look. Clockwise from Upper left: Brilliant red color of poison ivy leaves in fall; hairy vine of poison ivy; white berries of poison ivy.

Don’t you just love fall? If you know me at all, you know it is my favorite season. Not so much for pumpkin spice everything, but the cool, crisp weather — well, more like hot humid this year.
But no one could argue that the changing of the leaves in fall is breathtaking. But did you know that one of the most brilliant, crimson red leaves are that of poison ivy?
Yes, it is true. Poison ivy fall color is spectacular. And it is easily confused with the leaves of another climbing vine, Virginia Creeper. Both poison ivy and Virginia creeper are both native and have outstanding fall color. And, truth be told, Virginia creeper, although not poisonous like poison ivy, can cause some dermal reactions in humans, too.
The poison of poison ivy comes from its essential oil, urushiol. The reason I bring this to your attention in fall is, poison ivy is poisonous year-round, even in dormancy. Now it is not quite like the shiny, summer poison ivy leaf oozing with oil in July, but all parts of poison ivy have urushiol in them.
And if you expose yourself to the oily residue, congratulations, you could have poison ivy at Christmas dinner. But it takes a little more of a “relationship” with poison ivy to get it in the fall and winter when the leaves are shutting down and the vine is dormant.
But if you accidentally tear a leaf or, when pulling the vine, expose yourself to the internal parts where urushiol is still available, you can get poison ivy even in the coldest of winter. My first knowledge of this was when I would get calls in February from golfers who took the opportunity of mild winter weather to get a few rounds in … and they ended up with poison ivy.
It took me some time to figure out that they had hit balls into the less-tended, rough and swung their club right into some poison ivy, probably opening some of the leaves exposing the poisonous substance. Then they probably put that club back into the golf bag then later wiped their face or arm and spread the oil.
Virginia creeper vine also turns brilliant, crimson red in the fall, but the mature leaf is shaped totally different. It has five sections as opposed to the poison ivy’s three. Virginia creeper also is the larval food source for one of the most interesting groups of moths I have ever seen, the Virginia creeper Sphinx, the Pandorus Sphinx and the Nessus Sphinx.
Virgina creeper is a great groundcover, but its sap can cause a skin rash. The sap contains microscopic calcium oxalate crystals called raphides. These raphides with their sharp edges can puncture the skin and cause irritation and blisters in people who are allergic. Wearing gloves and long sleeves is suggested to avoid any issues.
Now on to the winter identification. But first a little helping poem. I am sure you have heard the ol’ campers’ mnemonic device that helps identify poison ivy, “Leaves of three, let it be.” Well add this to it. “Berries of white, run in fright!” and “Vines with hair, don’t you dare!” The former line I have heard before, and the latter, I made up.
So once those brilliant leaves of three have fallen for the year, just how do you identify poison ivy? By its fruit and its dormant stem. The fruit of poison ivy is clusters of off-white berries. Here is another good lesson: Never, ever, eat anything in nature because you saw an animal eat it. I am always surprised when someone tells me they thought if nature eats it, it must be fine. Yes, for nature, not so for humans. No.
But birds and other wildlife do love the berries of nature, whether native or alien. Berries help our wild birds get through winter. Viburnum, holly, pokeweed, and yes poison ivy and Tartarian honeysuckle all are part of nature’s winter diet. The fact that wildlife love these berries also accounts for most of the spread of the plants into no areas, including your backyard.
I had this happen at my home; I have several mature bushes that are quite thick, and low and behold, one fall when the leaves dropped off, I saw white berries. Unbeknownst to me, a poison ivy had set up shop inside my bridal wreath spirea. I quickly clipped out those berries so there wouldn’t be any additional bird propagation on my yard, then went to find the vine.
If you only know poison ivy as an herbaceous plant — non-woody, relatively easy to pull out, you may never have seen the mature version. Poison ivy matures into a strong woody vine that can climb trees. Good that it is easily identifiable. Poison ivy vine is full of small hairs all the way up and down the vine, and it is the only vine to have that characteristic.
As far as removal of poison ivy in fall and winter. It is actually a great time since there are no leaves, so less chance of getting the rash. My method of removing poison ivy, especially bigger poison ivy, is to, of course, wear long sleeves, long pants and gloves.
Also, if you have poison ivy that has become a vine, using a product containing Triclopyr 8.0% on the cut stem, will prevent the vine from returning. It is sold under many names, Triclopyr will be listed as the active ingredient. You paint the stump as soon as you cut it (I use one of those foam paint brushes for easy application).
Before I start cutting and pulling, I get a large garbage bag and flip it inside out. After I have cut and pulled the vines and stems, I put my hands inside the bag and grab the plant material, while pulling the inside out bag over the vines. That way I have no exposure and double protection.
Then tie up the bag and dispose of in the garbage. I know I have mentioned this before, but it bears repeating: never, ever burn poison ivy.
That oil that is the poison volatizes when burned, turning it into a poisonous smoke that can be inhaled, with tragic results.