I'm pretty sure they just sometimes fertilise crops you put down. You can't chose when it happens, it's totally random.
You can plant it for 5 brains, or you can mix 2 garden zombies in a zombie pot.
all sorts of zombies
That is when you harvest a zombie that is dead
You cant. Thats in Plants vs. zombies, not zombie farm.
12 zombies.
You can hold zombies in it.
just click on them ;)
by using the zombie pot at lvl 25
You combine two headless zombies in a zombie pot.
To store zombies.
Uh, no.
You get to mutate zombies!