I know someone who keeps the wild raccoons away by leaving a talk radio station running by his garden and green house. The sound of humans in the greenhouse frightens them.
The other way to keep them away is to scatter dog food all over the ground far, far, far, away from the green house. They can smell it and they will go to the dog food instead of the greenhouse.
Also you can trap them. Drive them 5 miles away and release them away from people.
