Poison ivy is a highly prolific plant. The slender vine grows along the ground for many feet until it finds a tree or shrub to reside on. The vine will cling to the tree trunk to grow toward sunlight. The plant has a three-leaf structure that extends from small branches. The old saying "Leaflets three, let it be" should always be remembered. Small flowers emerge just above the three leaves, and in the fall small white berries are seen at the end of the branches.
Locate a poison-ivy-rated herbicide. Consult your local agriculture extension service for their recommendations. Poison-ivy herbicide is different from a regular grass or weed herbicide. The poison-ivy type contains a detergent to remove the leaves' outer waxy protection. Roots to the plant grow far underground, and unless completely killed, the plant will come back in a few weeks to months. Contamination from the plant is so readily spread that herbicide control is the safest and most recommended method of eradication.
Mix the herbicide following the manufacturer's directions. It is best to go a little heavy in the mixture than too light. In other words, mixing the herbicide a little stronger is better than not adding enough of the plant killer into the sprayer.
Wear rubber gloves and perhaps a pair of disposable overalls or clothing. You may come into contact with the plant while spraying.
Apply the herbicide to the poison ivy on all exposed three-leave structures. The best time of day is during the hot afternoon, with full sun and when no rain is predicted for at least the next few days.
Observe the plants over the following week. Some herbicides may take as long as one week for the leaves to show any signs of wilting.
Apply a second coating of the herbicide after a one-month period to any re-emerging leaves on the poison-ivy plant. Perform this process during the hot summer months. The poison-ivy plant may take several applications of the herbicide in order to completely eradicate. Follow the manufacturer's labeling and safety instructions for their particular product.