Homemade Weed Spray (Non-toxic)

I can't take credit for this recipe. However, I've seen it posted on so many different sites that I don't feel bad about stealing and reposting.

(Sorry... I know the hose in the picture is annoying and distracting, but I had to set up a temporary sprinkler for some freshly planted bulbs. I could have moved it for the picture, but I'm not a fan of doing work just so I can re-do it when I'm done)