Kelp Grow is a brand of spray that appears in the episode "Giant Squidward."
The bottle is yellow with a light green burst effect and the product's name written in capital blue letters on it. The bottle also has a white cap and dispenser.
It is used to revive withered kelp. If it is sprayed on anything else, it will make it bigger.
Role in episode
After SpongeBob and Patrick witness Squidward using this spray on his kelp garden, the pair is amused by its ability to increase the size of things, so they decide to test it out on numerous objects like an ice cream cone and Gary's shell. They then decide to use it on Squidward by spraying a majority of it on his body parts, which turns him into a giant who has to give in to the Bikini Bottomites' commands to prove that he is nice, much to Squidward's irritation.
SpongeBob and Patrick think that if the bottle is turned upside-down, it will shrink things.