Greenhouses are ideal places for rats to take up residence. They can protect rats from the elements, provide them with food and offer countless hiding spots. As frustrating as rats can be, many greenhouse owners want to get rid of them without causing them pain. Luckily various strategies exist for keeping rats out of your greenhouse in a humane way.
Remove or throw away any crates, boxes, gardening equipment or other containers where rats may nest or hide. Move any wood stored outside the greenhouse to another location as wood piles are a favorite hiding spot of rats.
Pick up all garbage and garden debris from the greenhouse frequently. Place it in trash cans with lids so that rats cannot enter or take up residence in trash cans.
Stack greenhouse items on shelves, leaving sufficient space behind and between them. Avoid keeping items on the ground. This will help you to more easily inspect the greenhouse area for rats.
Clean up pet food and pet areas. Take pet food and birdseed out of the greenhouse if you keep it there, or store it in containers with tight lids. Remove food from nearby doghouses, and feed pets away from the greenhouse to avoid attracting rats. Clean nearby doghouses and pens frequently to eliminate rat hiding spots.
Close greenhouse doors and windows, and keep them closed at all times. Cover windows with 1/4-inch or smaller mesh screens. Tighten screens and windows using a screwdriver. Secure grates over all incoming pipes and drains by tightening them with a screwdriver.
Press a stainless steel scouring pad into any small cracks around pipes, vents or elsewhere. Caulk over the top of the scouring pad to fully seal all open spaces. Mice and rats can penetrate very small holes so make sure to fill all openings, even those above ground level.
Place a high-frequency, electronic ultrasound device designed to detract rats in the greenhouse. Change the sound pattern occasionally to prevent them from becoming resistant. Leave a window or vent open during this time so that rats can escape.
Sprinkle organic rat repellent throughout the greenhouse. Lightly sprinkle it over all greenhouse surfaces two times per week for two weeks for mild problems and three times per week for three weeks for severe problems. To maintain protection, reapply once every three weeks.