The people behind my house have poison ivy growing on their property. It has reached my 6-foot stockade fence and has climbed over to my property. We are highly allergic. Is there something I can do to kill what is on my fence and property? -- Pat Burke, Medford
Poison ivy (Toxicodendron radicans) is a nasty vining plant that contains urushiols, which cause an itchy, blistering dermatitis to those unfortunate enough to brush up against it. The urushiols remain a threat all year long, even on dormant plants that have lost their leaves, and can be transmitted to humans via gardening tools, clothing and pets. Even bona fide dead vines contain the toxin. It's good to know, though, that regardless of how ugly and contagious the rash looks, you can't catch it from touching someone else's rash. The plant grows on a vine just under the soil surface and can climb as high as 30 feet up trees and walls and along fences, attaching itself via aerial roots.
The first step in avoiding the plant is being able to identify it properly. Look at the photos on this page. Notice the leaves are made up of three leaflets apiece (hence, the childhood rhyme: "Leaves of three, let it be.") Even so, identification can be a challenge to the uninitiated. Though the leaves are always composed of three leaflets, their shapes can vary, and their edges can be smooth, lobed or toothed.
If you're certain you're dealing with poison ivy, you'll need to approach your neighbor about removing it, because pulling up the portion of the plant that has invaded your property will provide only a short-term solution, and it will only be a matter of time before it works its way to your side of the fence again.
The most effective means of removing poison ivy is to uproot it in March, after the freeze-thaw cycles of winter have softened the ground. Since you're allergic, this is not something you should take on yourself. You also should be careful to avoid contact with any tools or clothing used during the job. Long sleeves, pants and gloves should be worn, and all clothing carefully removed afterward, so as not to allow it to come into contact with skin. Clothes should be put directly into the washer and the handler should take a shower immediately. I recommend washing with Tecnu soap, which does a good job of removing traces of the resins.
Proper disposal is critical. Poison ivy should never be burned because the smoke would contain toxins that, when inhaled, would cause what would amount to a poison ivy rash in your lungs. It's not pretty. Bag the ivy up tightly and set it out with the trash.
Nonselective herbicides containing triclopyr or glyphosate can be used to kill the plant when it begins to grow in spring, but be aware that they also will kill every other plant in the area, including grass. Generally, the sprays are applied to leaves, which should wilt within a day, turn brown in three days and die within a couple of weeks. But repeat applications are often necessary. Always read and follow label directions carefully.
If you have a lot of poison ivy, consider calling in a poison ivy removal expert to protect yourself and to ensure its complete eradication.