We've all learned that little phrase, but even if you're careful, poison ivy may still catch you unawares. Toxicodendron radicans is native to the eastern half of North America and is hardy from far into Canada to the hills of Mexico. There aren't many places that this plant isn't at home. Anywhere there is a bit of sun and soil of dubious fertility, it manages to thrive, although it seems to prefer the edges of wooded areas, fencerows and abandoned fields. This places it perfectly for hikers, farmers and anyone clearing brush to come in contact with its leaves. With fall clean-up going on in most of our gardens, it is best to be aware of potential hazards. Birds love the small berries, so chances are, seedlings can sprout in flowerbeds and landscaping. Always wear gloves when weeding!
First of all, poison ivy isn't really an ivy. It has no botanical connection to the Hedera genus and in fact, has more in common with cashews or pistachios. This comparison may because of its tendency for its aerial roots to cling to surfaces, much like ivy does. It can scramble up trees, across fences and up wooden barns, so this vine has some of the same characteristics as the ivy. Another common mistake is confusing it with Virginia creeper. It also climbs walls and structures with the aerial roots, however the Virginia creeper has 5 leaflets, arranged in a hand-like shape instead of the three leaves of the poison ivy. Virginia creeper is sometimes noted for causing a rash, but in my experience, I've never had a rash or known anyone who has developed one after handling Virginia creeper.
Poison ivy is one of the first plants in the forest to change to autumn colors and the bright red leaflets are visible for quite a distance. The trunks of trees sport the pretty red leaves creeping upward and it is easy to spot them from the highway. The red is one of the most vibrant hues of autumn and if you have a wild spot where it can coexist peacefully with your family, then by all means, let it stay.
However, this is not a plant that you should encourage near your home. The sap contains the chemical urushiol that causes blisters and dermatitis wherever it comes in contact with your skin. It is so potent that even handling the clothing of another person who has been exposed, or rubbing the fur of pets will cause blisters to form. Some people say that scratching the rash causes it to spread, but that isn't the case. The areas of your skin that had the most contact will break out first, the areas that didn't have as much contact will follow shortly. Poison ivy is so potent that it doesn't have to be actively growing to cause a problem. Dormant vines in the dead of winter can be just as troublesome (ask me how I know). Also, remember that if you are burning brush that may contain poison ivy, that inhaling the smoke can blister your esophagus and lungs and is a very serious condition. Anyone who works in an area where it is believed that this plant can grow should immediately wash all clothing and take a shower before touching anything in the home. Doorknobs, phones and furniture can transfer the urushiol to other family members. Pets that roam in wooded areas where it grows, should be bathed before allowing them inside. The rash generally lasts from one to three weeks and products like calamine lotion dry the blisters and ease the itching. There is also a product on the market containing the chemical bentoquantam that comes in the form of a lotion. When used on the skin, it creates a barrier for the urushiol and prevents the rash. You can purchase this at most larger drugstores and it is advisable to use it if working in an area where poison ivy grows.
In the 18th Century, craftsmen used the sap as an additive to furniture varnish, but apparently that was a short-lived experiment, as the practice faded out quickly. The small, white berries were used as folk medicine to treat arthritis and rheumatism. Also, an elderly gentleman who stopped by as I was writing this said that years ago, it was said that if you ate the new leaves of poison ivy as soon as they appeared in the spring, you would be immune to it the rest of the year, but he stated he didn't believe that tale thank goodness! Please remember that it isn't advisable to ingest any part of this plant because of the toxic urushiol. Folk medicine cures should be taken with a grain of salt and even though there are legitimate treatments using herbs and plants, please do due diligence and never put anything in, or on your body without doing intelligent research.
Poison ivy is pretty in the autumn and I enjoy it from afar, I just don't allow it in my garden.
Images are my own and from PlantFiles