If you do not have the so-called green thumb and are not exactly the best when it terms of caring about your plants, you can help your little friends with a little help from egg shells. The ground up egg shells and water left over after you hard boiled eggs is great for plants.
Eggshells have a high amount of calcium, which plants absolutely love. Let the hard boiled-egg water cool, and then use it to water the plants. They will thank you for it—especially solanaceous garden plants (such as tomatoes, eggplants, peppers, etc.).
You’re not going to get as much calcium from the water, but grinding up the egg shells and adding them to the soil will make it more calcium-rich as well.