For your best natural defense against the poison ivy growing in your yard, buy a Spanish or Angora breed goat. This breed of goat enjoys poison ivy as a delicacy, for some undiscovered reason. While an effective solution, most suburban homeowners don't have the room or even the ability to keep a goat due to housing development regulations. For those homeowners, killing poison ivy naturally is still an option. Use just three substances found easily in the home or purchased at grocery stores for a simple, natural herbicide.
Measure 1 cup salt and pour it into a large pan, over a gallon in size. Pour 1 gallon of vinegar in the pan.
Heat the pan on low to medium heat until the salt dissolves. Remove the pan from the heat and allow to cool.
Add 8 drops of liquid detergent to the pan, once cooled.
Place a funnel on top of the garden sprayer. Pour the mixture from the pan into the sprayer through the funnel.
Spray the poison ivy with the mixture. Spray evenly and completely cover the poison ivy. Spray the mixture only on the poison ivy, as it will kill any surrounding vegetation it touches.