Tired of finding huge chunks of egg shell in your compost or garden beds, long after putting them in? If you're like me, you do your best to crush up the egg shells before throwing them in the composter, but they hold together pretty well, even after cooking in the compost tumbler for a few months!
Someone, somewhere, gave me the idea of using the coffee grinder to make "egg shell dust" and I've found this method to work very well. A food processor would probably also work fairly well, but I'm afraid the egg shells might be hard on the blades. We don't use the coffee grinder anymore since my wife started using the Keurig, so the coffee grinder is perfect!
I mixed the resulting finely ground egg shells directly into the garden as I planted my tomatoes this spring, to help combat blossem end rot. I also had tilled some bone meal into the bed during its initial preparation a few months ago.