Why you should save egg shells for your garden

Save your egg shells. They're an excellent source of nutrients for the garden and help repel pest. Egg shells are primarily made out of calcium carbonate, which is the ingredient found in agricultural lime. 

Fertilizer tea. Make an eggshell fertilizer tea, boil a gallon of water, and then add 10-12 clean and dry eggshells to it. For a stronger tea, add up to to 20 eggshells. Let the shells sit in the water overnight, and then strain the water. Pour the concentrate directly onto the soil to give plants a boost of calcium and potassium. You can do this weekly throughout the growing season. This makes a great fertilizer for houseplants.

Crushed shells. Crush the shells using your food processor or a rolling pin. Add the shells to compost or mix well into the soil. Collect the shells throughout the winter so you'll have adequate supply. After the eggshells are crushed, sprinkle them around the areas in your garden where you are having problems with slugs and other crawling pests.

Egg shells help stop blossom end rot for tomatoes. You can also feed them to your chickens.