I was just letting crabgass take over my lawn in the summer because I didn't want the granular stuff laying around everywhere until the crabgrass showed up in just certain parts of the lawn. This sprayer means you can just hit the weeds after they emerge and you don't have to worry about the right dampness when applying the solid stuff. I do it in the spring for dandelions and onion grass and summer for the crabgrass. So you buy it without the crabgrass control ingredient in the spring. Click on image for link.