Master Gardener Explains How to Avoid Poison Ivy

“Leaves of three, let it be,” my mother always told me when I was playing outside as a child. 

As a gardener, that advice comes in handy.  Unfortunately, even with attempting to avoid the leaves of poison ivy, poison oak and poison sumac, I still managed to have several severe reactions after coming in contact with them. 

One of those times, we were clearing brush in the woods during the winter and I must have come in contact with the dormant vines.  When the vines are mature, they have a hairy appearance that is very distinct but when they are smaller, they are harder to distinguish.  The other times, I believe I came in contact with the oil by petting my dog.  Dogs and cats can carry the oil on their coats after brushing against the plants and if we pet them, we develop the irritating rash.

The rash from poison ivy, oak or sumac usually starts out with red blotches but as we scratch, it develops into painful itchy pus-filled blisters. 

In the case of poison ivy, the rash is caused by an oily substance called urushiol that is carried in the leaves, stems and roots.  One billionth of a gram can cause a rash.  When you come in contact with it, you have about 15 minutes to wash it off with soap and water in order to avoid a reaction.  If you don’t, your body develops sensitivity to it and over the next 24 to 48 hours, you will develop a rash.  

If left untreated, the resulting sores can become infected.  My husband had such a severe case a few years ago, not only did his doctor prescribe steroids to help heal the area, he also prescribed antibiotics for the resulting infection. 

Besides causing severe infections, poison ivy can also be dangerous when any part of the plant is burned and resulting smoke is inhaled.  Firefighters in particular have to be very careful because once this smoke is inhaled, it can cause severe irritation to the lining of their lungs, mouth and nose.  Also, their faces and any part of their body exposed to the smoke will develop the rash.  

In summer, there is a sharp increase in the number of cases reported because we spend more time outdoors.  About 90 percent of people will develop an allergic reaction to poison ivy.  Approximately 55 million Americans a year experience reactions to poison ivy, oak and sumac resulting in 1.5 million emergency room visits annually.  

Poison ivy is a woody plant with three-leaf clusters.  Leaves can be smooth or notched. The plants produce white berrylike fruit that produce even more poison ivy plants as they come in contact with the soil. 

To eradicate poison ivy, wear gloves if you are going to pull it by hand. Some gardeners use Round Up to treat it but I have found this requires several applications. I have had the most success with a product called Brush Be Gone.  When using such highly toxic products, be sure to closely follow package instructions.

There are several “look alike” plants that grow in our area such as Virginia creeper and blackberry vines.  If you are unsure of whether to avoid such plants, the best advice is still, "Leaves of three, let them be!”