How to Keep Rats Out of a Greenhouse Without Using Poisons & Traps

Visit the greenhouse at least daily. Rats and other rodents are naturally wary of humans, so the scent, sound and sight of you may be enough to run them off.

Level the ground around the greenhouse. Remove stacked wood, mow tall grasses and dispose of abandoned household items. These are all places rats may find shelter.

Examine the greenhouse flooring and walls for holes. Even a half-inch hole is large enough for many rodents to squeeze through. Plug the holes with steel or copper wool, securing the material with glue or duct tape. Rats, mice and other rodents will resist chewing through this material.

Soak cotton pads in peppermint oil. Place the pads around plant trays, in corners or in other areas you suspect rats to congregate. The scent of peppermint is a deterrent.

Install an electric ultrasonic device inside the greenhouse. Such devices emit high-frequency sound waves undetectable to human ears but irritating to rodents. This strategy works best before the rats have appeared. If your greenhouse is already infested, the rats may become immune to the sound.

Get a cat. Set up housekeeping for the cat within the greenhouse, including its bed, litter box and food. Once the cat is established in its environment, it will instinctively turn to hunting for rats and other invaders.