Plants vs Zombies 2 Dark Ages level 12

I am having trouble passing level 12 in Dark Ages....How do you keep a plant alive if it only has limited life? Is this a bug? Maybe I'm slow and the answer is right under my nose. I am stumped and I HAVE STOPPED PLAYING because this is very discouraging to me. Someone...Anyone....please help! I am a PvZ fan, but I am so close to deleting PvZ2 because of this and some other darn near impossible levels.
Any help given is greatly appreciated.

UPDATE: I have the answer!! Thank you!! Thank you! Thank you! 😉👍