Poison sumac (Rhus vernix) grows in damp and swampy wooded areas in the Southeast, as well as in some pockets of the Northeast. The Rhus genus, which includes poison ivy and poison oak, is native to North America. It's sometimes classified as Toxicodendron, meaning "poison tree" in Greek. If you find this plant on your property, you'll want to get rid of it to avoid contracting an itchy and debilitating rash.
On each stem, poison sumac has five to 13 leaves, which are smooth around the edges. The plant's stems are red, and its leaves are green in the summer and yellow to red in the fall. It has green berries that turn white in the fall and grow in small clusters on individual stems.
When to Remove Poison Sumac From Your Garden
Although there is no totally safe time to eradicate poison sumac, the best time is in the winter or early spring before the last frost. During this time, the plant contains the least amount of the sap that can cause adverse effects. Even so, you must wear protective clothing, tuck your pants into your socks, and tuck your sleeves into your gloves before proceeding.
Equipment / Tools
- Protective clothing
- Rubber gloves
- Pruning shears
- Garden hose
- Pump sprayer
- Trash bags
- Flattened cardboard, newspaper, old carpeting, or tarps
Removing Poison Sumac by the Roots
One organic method to get rid of poison sumac is to pull it out by the roots. The roots must be disposed of in the trash.
Never burn poison sumac clippings. Inhaling fumes from burning any poisonous plant can cause far greater health problems than the rash that can result from skin contact.
Pull Growth and Structures
Wearing protective clothing, including boots and rubber gloves, pull the plant away from any surrounding growth and structures. Trim it back to the ground with pruning shears. If the plant is old, its vines could be intertwined with foliage and structures nearby. Use your shears to free it, and then bag all the clippings.
Spray the area with a hose to saturate the soil. Wait about 30 to 60 minutes to allow the water to soak in. This will make it easier to pull up the roots.
Dig and Pull
Using a shovel, dig around the root ball, prying it up from underneath. Then, with gloved hands, pull all the roots from the soil, and place them in a plastic garbage bag.
Smothering Poison Sumac
Smothering entails cutting the sumac plant close to the ground and then placing newspaper, cardboard, old carpeting, or tarps on top. However, even after you kill the plant, it will remain toxic. So be careful when disposing of the plant and its roots after removing the smothering material.
Using pruning shears, trim the plant to the ground. Discard the trimmings in a plastic garbage bag.
Next, take cardboard, a tarp, or another smothering material, and cover the ground where the plant once lived. Take care to cover the surrounding area where roots could throw up new vines. Spread mulch over the smothering material, and let it sit for at least one growing season.
After at least one growing season has passed, uncover the area, and dig up the roots using the same precautions you would for a live poison sumac plant. Discard the roots in a plastic garbage bag.
Removing Poison Sumac Using Herbicide
As a last resort, you can use herbicide to effectively get rid of any poisonous plant. However, these products often contain chemicals that can be harmful to people, animals, and the environment.
Choose a Sunny Day
Herbicide eradication works best on sunny days with little wind. Make sure there is no rain in the forecast that will wash off the chemical before it kills the plant. Don't spray if rain is predicted within 24 hours of treatment.
Prepare your herbicide according to the package directions. Some products might need to be mixed with water inside a pump sprayer. Always wear protective clothing when you're handling herbicide.
It's ideal to spray the poison sumac when it's fully leafed out. This means going after it during the height of its growing season, which is generally late spring to mid-summer. If the sumac vines have engulfed a tree, carefully apply the herbicide onto the leaves to avoid damaging the tree with overspray.
Poison Sumac Removal Tips
Once eradication is done, spray down your boots and gloves with a strong stream from the garden hose. Take off your clothing, and place it directly into the washing machine, washing with hot water. Also, immediately shower to wash off any sap from your body and hair.
If you're using herbicide, understand that it might kill wanted garden plants. In addition, overspray near a vegetable or herb garden can make the food unsafe for consumption.
No matter what method is used, it might take more than once to achieve complete success. Continue to keep an eye out for the plant in case it decides to return.
Treating Poison Sumac
What makes poison sumac so poisonous? The answer lies in the oily sap—called urushiol—that runs through all parts of the plant. Any exposed part of your body that grazes against poison sumac can release this oil. Plus, the contact doesn't have to be direct. For example, a dog that runs through poison sumac can transfer the oil from its fur to your skin.
If poison sumac touches your skin, immediately apply rubbing alcohol to the area, and then rinse thoroughly with water. This action can remove the urushiol before it takes effect. Bur if a rash appears, treating poison sumac is similar to treating a poison ivy rash. Some people obtain relief with over-the-counter remedies, such as hydrocortisone cream and calamine lotion; others require a visit to a physician to obtain stronger remedies. For mild to moderate cases, about one to two weeks is needed to get rid of the rash.
Beware of Poison Sumac (Rhus vernix). University of New Hampshire Cooperative Extension
Poisonous Plants - Recommendations. Centers for Disease Control and Prevention
Gladman, Aaron C. Toxicodendron Dermatitis: Poison Ivy, Oak, and Sumac. Wilderness & Environmental Medicine, vol. 17, no. 2, 2006, pp. 120–128., doi:10.1580/pr31-05.1