Before you call an expensive lawn service to come out and treat your lawn with a bunch of chemicals, try a simple and effective way to kill poison ivy with vinegar and a couple other household ingredients. You may never have to buy pesticide again, or at least you will be able to save some money by making your own solution at home.
Mix the 1 cup of salt with the 1 gallon of vinegar in a pan and heat it up until the salt has dissolved. The easiest way to do this is by placing the pan on a stove and turning on the heat.
Let the vinegar and salt mixture cool and then add in the liquid detergent. Mix this together and pour the entire solution into a spray bottle. If you don't have an empty spray bottle, use an old empty bottle of Windex or anything else that comes in a spray bottle. Thoroughly clean the bottle before using it. You can also just simply pour the solution onto the poison ivy, but be careful that you don't run out by pouring too much.
Spray the poison ivy with the mixture. Keep in mind that this solution will kill all of the plants it comes in contact with, so only spray this over the poison ivy or other vegetation that you wish to kill.