Leaves of Three...Poison Ivy!

If you have read the article on shade gardening, you will remember I've Photo Courtesy of USDA Free Photos. William Justice, Photographer mentioned that shade and woodland gardening were not the same. I also said that woodland gardening presented certain challenges. You are looking at my Number 1 challenge in trying to develop a woodland garden: Poison ivy.

Poison ivy and its relatives, poison oak and poison sumac, are herbaceous perennials that secrete a substance known as uroshiol. This is the bane of about 60 to 80% of the population. It is the number one cause of allergic reaction in this country, allergic dermatitis. For being number one, it's a doozy, to say the least!

Something I was not aware of: It is native, of course, to much of the U.S. and Canada. However, it can also be found in Mexico, Central America, and the Bermudas. Asia, Japan, Taiwan, and parts of China are home to poison ivy, as well. In a sort of reverse scenario, it has recently crossed the pond over to Europe. (I am truly not feeling smug about this, but let's face it. Many of our plant woes have resulted from the intentional or inadvertent importing of such European pains-in-the-butt as loosestrife, dandelions, etc. It seems rather ironic that one of the nastiest of our plants has made it overseas).

Anyone who sets foot out back or goes to a park needs to know how to identify this plant. It is not restricted to the wilds, by any means. When I lived in the heart of the city, I can remember my neighbor developed such a severe reaction after pulling it up along the fence line and then burning it, she ended up in the emergency room. When it was all over, she said she didn't know it was poison ivy, and she never knew it could grow in town! It would grow into the walls of our houses, if it could!

Recently it has been determined that poison ivy and poison oak are related, and poison sumac is not a near relative. That matters little when all three plants cause the same misery. Geographically, poison oak is found primarily in the Western Regions of the continent, poison sumac generally grows in the far Northern reaches of the country in bogs. Poison ivy grows almost anywhere. There are two main varieties of poison ivy found in the U.S. and Canada, but it means little to know which one you have tangled with, the results are the same. For simplicity's sake, I will consider it as one plant variety only.

Poison ivy can grow as a vine, bush, or it can scramble along the ground. All parts of the plant are poisonous. Its drupes, or berries, are waxy white. Birds and other wildlife browse on the fruit and leaves of this plant.

The leaves of poison ivy are trifoliate and in three leaf clusters. It can have a smooth or serrated edge. The number one plant it is confused with is the Virginia Creeper, a harmless woody vine that has its leaves in groups of five.

Because its roots run along the underground, poison ivy is difficult to eradicate. It will send up shoots all along its root system. Grubbing out a piece of it isn't effective since the rest of the root remains and it will resprout further on down the line. I have found that using the following formula, I can get effective and relatively quick elimination of the poison ivy. Apply carefully, taking care not to spray other plants or the soil:

Poison Ivy Control

1 cup salt
8 to 10 drops liquid detergent
1 gallon vinegar

Combine the salt and vinegar in a pan and heat until the salt is dissolved, then cool. Add detergent. Use a spray bottle to spray the vegetation only. Do not apply until it is dripping onto the soil, simply apply to get the leaves wet, and take care not to apply to beneficial plants or soil, as this will kill everything!

Repeated applications will be needed, and then there is the problem of removing all those dead plants after they are killed. You will need to exercise care and bag the remains into plastic bags. Do not throw the dead plants on the compost heap and definitely do not burn them! The urushiol in all the plant parts can remain potent for five years or longer. Burning releases the oil vapor into the air, which can be inhaled with disastrous results.

If poison ivy is growing as a vine, chop it off about six inches above the base, and paint the stub with organic weed killer. If it resprouts, spray the leaves, and keep doing so until it is dead.

When out in the wilds of your woods or back yard, there are many products developed to help provide a skin barrier for protection. There are also products that you can use to wash yourself with after exposure. They help, but the best practice I have found is to get the clothes off and into the washer and jump into the shower immediately after hanging out in the woods, and the sooner the better.

This is one plant to have a grudging respect for. We have to remember it was here long before any of us were, and it will be here long after we are gone. At least it is good for the birds and the beasts, and it is pretty to look at in the Fall when it turns orange and red. Pretty from about 50 or so feet away, that is...