Can the police search my garbage without a warrant?

A lot depends on where your garbage is located.  In the 1988 case of California v. Greenwood, the U.S. Supreme Court held that the police did not have to have a warrant to search a plastic bag full of garbage located on the curb in front of a private home where the bag was located outside the curtilage of the home.  Such a search violates the fourth amendment to the U.S. Constitution only if the person discarding the garbage has an expectation of privacy in his garbage that society accepts as objectively reasonable.