Mice in My Greenhouse

I don't know the design of your greenhouse but perhaps it can be sealed so that rodents cannot get in. There are a number of passive traps designs in youtube, that can decimate even the most prolific rodent population. But if artisan massacring of mickey's brethren is not acceptable, perhaps you can get some help. Here is a photo of the one that helps keep my orchid growing area rat free. As a pleasant added bonus, I haven't had plant theft in ages.

 

This is awesome.

 

Yes, I had garter snakes in my greenhouse. They were quite effective at keeping the rodents under control.

They were not, however, a deterrent to groundhogs, so trapping and relocation was necessary.

 

Your best bet is to make the greenhouse impenetrable like others suggested (seal any gaps or holes, wire screen on vents / windows, etc). Then you'll need to keep traps going and/or use poisons (if there are no pets / children around) to ensure there's not a breeding colony in the greenhouse.

Mice use urine trails to communicate and navigate with. The smell of urine protein / pheromones of a past infestation will attract newcomers, which may explain part of why there seems to be an endless supply. There are also commercial products you can spray which neutralize the urine smell, and there are homemade remedies that may help.

Living in farm country where household invaders are a fact of life, it's very common for people to plant various kinds of mint, and especially peppermint, around the foundation of their houses. Apparently it acts as a deterrent for mice. Folks also spray peppermint oil indoors or put out peppermint oil diffusers in areas where the mice scamper indoors. It won't get rid of mice if they're already there, but apparently it can dissuade them from coming back.

 

We have had great success keeping mice out of our cottage by placing moth balls as well as bait stations around the perimeter. Moth balls seem to be particularly effective.