Start an eco-friendly herb garden
Use unwanted eggshells as a natural fertilizer or even as pots to house seedlings.
Eggshells are mainly made of magnesium and calcium, and make excellent compost. Add crushed eggshells to enrich potting soil, or use the shells as pots for growing herb seedlings – when the seedlings begin to mature just plant the entire shell and the herbs will outgrow the shell naturally.