I assume you mean killing Poison Ivy in your yard. First make sure it’s Poison Ivy. So remember this saying, leaves of three stay away from me. Before you tackle this problem make sure you are dressed right with gloves on, a long sleeve shirt and pants. You should try to cover up as much of your body as possible. Now that you are dressed right, you should cut the plant now as far as you can and then spray it with a weed killer, then dig it up from the root. If you don’t get the root up it’s just going to keep coming back. When you are done make sure you put your clothes directly into the wash, you don’t want to come in contact with them later and end up getting Poison Ivy from off your clothes.