How do I clear all the grass squares have been trying for ever seems impossible?

This level is impossible. I read the tutorial on the game's settings and I STILL can't clear those grass squares in the limited # of moves they provide bc the darn grass squares keep spreading. I too am about to be done with this game.

The rocket is a good way to clear the grass. Same with the balls that turn into bombs as they clear the grass when they explode

In some of the levels only cross into square once. I am in a higher level and they keep reappearing and I haven't figured it out