I have been carefully breaking off just the top third of the eggshell, rinsing out the larger part, drying and saving to plant seeds in this spring. I am hoping the shell will be enough space to start seedlings and then I can put the whole thing in the ground. Recently I read someplace that you can save the shells, bake them, grind them up and mix in with your chickens feed for extra calcium. I have been saving shells to try this but I don't know how long to bake them or what temperature to set. Has anyone done this? Any advice would be appreciated. Any other ideas for recycling egg shells? Thanks so much.