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Tuesday - April 19, 2005

From: Blanco, TX
Region: Southwest
Topic: Invasive Plants, Problem Plants
Title: Methods of controlling poison ivy
Answered by: Nan Hampton


What do you suggest for controlling poison oak (ivy)?


Since many people are sensitive, some severely, to poison ivy (Toxicodendron spp.), it is not an easy plant to control. If you have a small amount of poison ivy, the sooner you start the easier it will be to control it. The method you use to control it will depend on your sensitivity to the urushiol oil from the plant that causes the itching. If you know that you are sensitive to the urushiol, you might be wise to hire someone who is not sensitive to remove the plants since the most ecologically friendly method for eliminating them is to pull them out of the ground. Pulling them up should include getting as much of the root system out of the ground as possible. The plants will come out of the ground easier if the ground is wet. You (or the person who is removing the plants), even if you believe you are not sensitive to urushiol oil, should protect yourself well while doing this. You should wear gloves, long sleeves, long pants, and boots or shoes with socks. To protect yourself even more you can put your gloved hand in a plastic bag before you grasp the plant to pull it out of the ground. As the plant is pulled out of the ground, the plastic bag can be pulled over the plant to cover it. After you have disposed of the secured plastic bags of plants in the trash, you should thoroughly wash all clothing and yourself. If the plants resprout from any roots that were not removed, you will need to repeat the procedure and try to dig the roots out of the ground. If you are dealing with a large amount of poison ivy to remove, pulling it up may not be practical. In such a case, cutting it near to the ground with long-handled clippers or equivalent device would be better. Shoots will still sprout from the roots, but continued cutting of the shoots should result in starving and killing the roots. It is not recommended to mow the plants since this would shred the plant releasing more of the oil and spreading it everywhere a cut piece is deposited. Burning is also not recommended since the windborn ash from the burning will contain the oil. Tilling the plants under will get rid of the immediate problem but unless the roots are removed, the plants will resprout. Incidentally, if your poison ivy is a vine that has made its way up into a tree, you would be better off severing the vine from the roots in the wintertime when the plant is dormant and the leaves have fallen. Otherwise, you are going to have a tree full of rather unsightly dead poison ivy leaves.

Although we do not generally recommend using herbicides, in the case of a plant that causes severe physical distress like poison ivy, there are herbicides that can be applied if done in a judicious manner. After removing the plants and as much of the roots as possible, you could treat regrowth by painting small amounts of herbicide on sprouting leaves. Painting restricts the herbicide to the plants you want to kill and not to nearby desirable plants. It also eliminates the amount of herbicide you are releasing into the environment. You can read about appropriate herbicides and other methods of control of poison ivy in articles prepared by the Ohio State University Extension Service.

If you have bare skin that has been exposed directly to poison ivy plants, washing with soap and cool water should remove most of the urushiol. Avoid warm water since it may help the oil penetrate the skin. There are products that reportedly remove the urushiol oil from the skin after exposure that you can find by googling "removing urushiol oil".


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