Board Thread:Plants vs. Zombies 2: It's About Time/@comment-26210337-20150219224725/@comment-24275721-20150222141105

The problem is that you have chosen plants whose Plant Food effects cannot leave the screen and are blocked by the boundaries of the lawn.

The only plants that could have saved you in this situation were the ones that have projectiles leaving the screen (like Coconut Cannon or Peashooting plants)