3. Give Your Garden A Calcium Boost My blender rarely sees daylight, but now it might just get the chance to see the kitchen counter with this genius tip! Im starting to understand the idea behind compost a little more now that Im dabbling in the garden, so this just makes a lot of sense to me. Just like grinding your food makes it easier to digest, grinding eggshells makes it easy for your garden to absorb the calcium egg shells provide.