Poison ivy plays an important role in nature. It provides cover for birds, and food with its berries. It prevents erosion. However, for humans it plays a drastically different role in our lives. It is a source of irritation and misery. Either you have a reaction that involves terrible welts, itching or blisters, or it is so mild that you don’t even notice you have come in contact with the plant.  I used to be one of the latter.  Consistent exposure to the plant over years of gardening has made me more susceptible to its toxic oil and its consequences. With over 80% of the population being allergic in one form or another, it’s best to learn the major identification points of the plant, and how to avoid  its miserable affects.

Note the different shapes of Poison ivy leaves. Some are round while others are more jagged.

In a recent commercial for a super-fancy cell phone, a new “how-to” application was introduced for identifying Poison ivy.  Well, turns out that the plant shown in the commercial wasn’t Poison ivy, just a cardboard cut-out laying on a bed of innocent plants. It was a quick shot, and I hope that people don’t use that as their guide.

Although this cardboard plant does have three leaves, it is sitting on a bed of harmless plants.

Poison ivy can be sneaky. It can grow in many forms, in all different landscapes, from the deep woods to the sandy dunes. It can often be found as a bushy shrub (Toxicodendron rydbergii), or a single large vine climbing a tree (Toxicodendron radicans). The two species often interbreed, and grow in the same location, so they are an equal danger. Even the plant in its smallest form can cause a reaction, as it is thought to have more concentrations of the toxic oil urushoil in its leaves for protection.

This particular plant is climbing, in bush form, and trailing along the ground.

The old saying “leaves of three, leave it be” actually does apply in some sense, but not all plants with three leaves are bad. Poison ivy has a compound leaf made up of three leaflets. The two side leaflets are the same size, with the top leaflet being slightly up the leafstalk and a bit smaller. Similar harmless plants are Virginia Creeper (berries are poisonous if ingested), Box Elder, and Wild Blackberry.

Box elder leaflets tend to be situated further apart than Poison ivy.

Note serrated edges on the Common blackberry. Poison ivy will never have a serrated edge, just rounded notches.

Virginia creeper looks similar to Poison ivy. It also changes color in the fall, and grows along the ground and up trees similar to Poison ivy.

Poison ivy is generally red in the spring, green in the summer, and then changes into red, yellow and green in the fall.  Plants may be fully shiny or just have one leaf that is shiny, so it is best not to judge by their shine. If the leaves are hairy it is not Poison ivy. Mid-summer they have clumps of green to white poisonous berries with a waxy coating on them.

Poison ivy berries are an excellent source of food for birds. Very toxic to humans.

Leaves may be deeply notched to only slightly lobed with rounded sides. They can be as small as your thumbnail when they first appear out of the ground, to as large as a your hand. Leafstalks tend to be a reddish-hue color, but that is also not always to case.

Note the reddish-brown hue of the leafstalks. Note how leaflets in back have notched edges, and in the front they are smooth.

Another saying to keep in mind is “Hairy rope-don’t be a dope”! Poison ivy can grow in a vine form. When it does, it clings to trees with hair-like aerial roots. The vines can be as big as two-seven inches across depending on age.

Poison ivy have aerial roots that cling tightly to trees. You should avoid contact with roots with bare hands.

Urushoil can stay on your clothes, shoes, and tools for over a year. It is therefore extremely important to thoroughly clean them after you have come in contact. Urushoil can also be transferred to humans via pet fur. If you think you have come in contact with Poison ivy, rinse your hands immediately with cold water. It is best to rinse within the first hour of contact because the oil has not had a chance to soak in. Avoid using both soap and hot water. Soap will bond with the oil, and then bond to your skin. Hot water will open up your pores and also let the oil in. Rubbing alcohol is a good way to help remove the oil from both your skin and tools. Wash clothing several times in cold water. Use bleach if you can.

The culprit: Urushoil. Make sure to wash clothing, tools and pets after contact. Urushoil can stay on contacted items for years.

Never mow or burn Poison ivy. Urushoil is found within the plants leaves and stems at its highest concentrations. Breaking a leaf will cause it to release the oil into the air. It can be inhaled, and bond to your skin from the air. This can cause serious illness and land you in the hospital.

Poison ivy is best removed in the fall. Make sure the person working with the plant is not allergic and takes all the necessary precautions. Laying a dark cloth over the plant for several weeks is a good option. Cutting the plant at the base works too, but can take several years to be effective. Can you get a goat? They love to eat Poison ivy! Ok, so if getting a goat isn’t the best option you can also try a non-selective herbicide such as Round-up. Round-up and Ortho make products geared towards Poison ivy and other hard to control brush.

Round-up and Ortho both make products for Poison ivy control.

If you have a rash, now it is fine to rinse with warm or hot water. This can alleviate some of the itching. Jewelweed, a native Michigan plant can be ground up and applied directly to the rash. Jewelweed will help the itching, and it has a cooling affect as well. I have found that the laundry soap Fels-Naptha works wonders on Poison ivy on the hands. I replace it with my normal soap for hand-washing when infected. It should not be used for long periods of time as it contains Stoddard solvent (mineral spirits).

Jewelweed grows in Michigan wetlands. It can be used as a relief from Poison ivy.