Crushed egg shells in the garden: Keep egg shells in refrigerator, when you've collected quite a few crush and sprinkle them near your plants to help prevent crawling insects and to add calcium to the soil.
Tomatoes need calcium to achieve their full flavor potential, and calcium is often greatly lacking in our soils. 95% of a dry eggshell is calcium carbonate. When planting your tomato plants crush up (to powder) about 4 or 5 egg shells and put them in the bottom of the hole. Then plant your tomato on top. They provide calcium and prevent blossom end rot.
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! I’m starting to understand the idea behind compost a little more now that I’m 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.