I was answering this Q, and proposed 2 Lightning Reeds as a way to kill 3 Camel Zombies.
However, I'm unsure if they can be killed by just 1 Lighting Reed (with no other plants).
So, if we have a Lightning Reed on leftmost square, and 3 camel zombies coming at it, will it be able to kill all 3 alone?
No other plants, no other zombies, no plant food.