How do you rid a yard of yellow jackets?

Around 8:00 PM I was outside watering my mom's flower beds and when I got to about the middle of our house I watered a shrub and a swarm of yellow jackets attacked me and I sustained 8-10 stings. I immediately fled the area and took cover inside. Then, I was walked back to the garage and out of it and heard buzzing all around, so I am worried the problem is pretty serious. I really want to get rid of them because it makes watering the plants impossible. Are they underground or in the plant I last watered prior to being stung? The only thing that makes me think the problem may be a bigger issue is that a little over a week ago I killed a larger yellow jacket trying to burrow in a hole on the complete other side of the home, so I think they are everywhere. PLEASE HELP!