If you like to give your garden a head start by planting seeds indoors in early spring, consider starting them in some eggshell planters. Eggshell planters are porous, compact, lightweight, and completely organic. Once the seeds are planted, they require very little care. When the seedlings are ready, they can be planted in the garden, eggshell and all.
Crack each egg about two-thirds of the way up on the small end, with the dull side of a table knife. Rinse the shells carefully and lay them on a layer of paper towels. When the shells are dry, poke two or three small holes in the bottom of each one, using the tip of a knitting needle or skewer.
Fill a tray with damp sand, which will be a bed for the eggshell planters. Fill the eggshells with potting soil and nestle each eggshell into the bed of sand up to mid-shell. Plant two or three seeds in each eggshell.
Cover the tray with plastic wrap and put the it in a sunny window. Keep the sand moist at all times, but don't water the soil. The moisture will soak into the egg through the holes in the bottom.
Remove the plastic once the seeds terminate. Leave the shells in the sunny window, and continue to keep the sand damp until you're ready to plant the seedlings outside.
Plant the seedlings outside after the last frost of the season. Dig a hole for each seedling, and plant the eggshell planter in the hole. You don't need to remove the seedling from the shell; just crack it lightly and the plant will grow through the cracks in the shell, which will eventually dissolve.