How to keep squirrels out of container plants?

Little bastards already ate all the flowers off my tulip plants now they are digging around in my tomato and pepper plants. I read to boil a chopped up onion and jalapeno with two tablespoons each red and black pepper and spray the dirt periodically to ward them off but I am concerned it might hurt the plants. Any ideas? I sprinkled some crushed red pepper in them yesterday so I will see if that seems to help.