The vinegar is what kills the weeds, but the dish soap holds the vinegar in place so it stays on the plant instead of running off. This works great on grass or weeds in sidewalk or driveway cracks, too. Best time to spray is in the middle of the day when the sun is hottest.

Ingredients
1 C. of vinegar
1/2 C. of regular dish soap (not dishwasher detergent)
Fill the rest of the bottle up with water.

Directions
Use a funnel to place the following ingredients in a medium spray bottle approximately the size of a quart, but it doesn't have to be exact. Shake well before each use. Spray mixture directly on the weed itself; if weed is out in the yard, be careful not to spray
the grass!