Poison ivy (Rhus radicans) is known by many other names including climbing sumac and poison oak. Before killing what you think may be poison ivy in your yard, you should first be sure it is in fact what you think it is. Poison ivy has three leaflets protruding from the stem. The leaflets are almost always smooth, but they can be either glossy or dull and the edges are either smooth or rigid. On just one poison ivy plant, the leaves may all be similar or they may vary. Fortunately, once you identify your plant as poison ivy, there are several ways to kill it.
Pull out the poison ivy when the soil is wet, such as the day after it rains. Wear gloves, old clothes and goggles. Grab the ivy near the base and pull up the roots slowly to get them all before it breaks. If you are sensitive to poison ivy this may not be a good option for you.
Cut the plant down with garden clippers. Then, repeat as it grows. This will eventually starve the ivy since it will be unable to photosynthesize sunlight into energy. Again, wear protective gear and if you are sensitive to poison ivy, this may not be the best method for you.
Apply an herbicide that is labeled strong enough to kill poison ivy. There are many herbicides with different potencies and ingredients. Roundup, Amitrol and Weed B Gone are just a few examples of companies that make an herbicide good for poison ivy. To apply the herbicide, legally and for your safety, you must follow the directions on the label.