8. Fertilize, Fertilize, Fertilize. Crushed eggshells are packed with calcium and other minerals, so they are a fabulous compost in your garden.
9. Pest Control. Slugs, snails and even deer aren’t big fans of eggshells — scatter then around the garden to deter those pesky pests.
10. Get Your Tomato Plants in Tip-top Shape. Tomatoes can get blossom-end rot as a result of a calcium deficiency. You know what’s full of calcium? Eggshells! Put some at the bottom of the hole when you’re transplanting them to prevent it.
11. Feed Your Indoor Plants. Place some eggshells and tepid water in a lidded container in a cool, dark place. Let it sit for a few days before watering.