The Flower Grenade is the latest weapon available for the guerilla gardener. Are you annoyed by a neglectful neighbor's yard? Perhaps you're fond of a traffic island with arable soil?
Either way, just chuck a Flower Grenade at it. The thrown explosive willl break open, detonating shrapnel in the form of buttercup and poppy seeds. And then, um, flowers will grow...and that'll be cool and stuff.