For small enemies, right next to them is fine. For larger ones, throw purples on top of the enemy. --- Brightly-colored half-plant half-animal carrots that have various elemental resistances and live in flying Onions = Pikmin
I threw all of my purples on a Spotty Bulborb (I'm assuming I did since they were on top of him) and he woke up and started chowing down on all of my purples. --- "Really? Are you sure he doesn't normally speak in pirate?"
Are you sure they were on top of the Bulborb? If they were thrown in top, they would've stunned it. Try again, and see what happens. --- Pikmin CYOA! http://www.gamefaqs.com/boards/633263-pikmin-3/64012311