Night of the Pet Zombies (Deadtime Stories, No. 16)

the long version

Eddie is stuck with the worst science project ever - thanks to his best friend, David, who insists that growing a couple of plants will be simple. But growing plants isn't easy for Eddie and David, who have never been able to keep any plants alive. Eddie is sure they're going to fail the science project - until a TV ad leads them to MIracle Life, a brand-new formula guaranteed to raise plants from the dead. The problem is, Miracle Life starts pumping life into more than just their science project...