User blog comment:TheHandsomePlant/(SPOILERS) Full leveling data of all plants (5.7)/@comment-11660317-20170211112219/@comment-30747734-20170211180224

it means that when Grave Buster done desrtying a grave it will explode dealing similar damage to Cherry Bomb LVL1 in a 1x1 area

https://youtu.be/LlYvTD7Bqbk?t=41s