5. Egg Shells
Best places to shop: Costco and local grocery stores.
Eggshells can be reused as seed starters, with an average price of $1.48 per dozen.
Before using the cracked eggshells, make sure to clean them thoroughly. Then place them in a paper egg carton. Fill each shell with soil and add a few seeds to the egg pots.

Eggshells as Seed Starters @ausobn/Pinterest
Follow the seed’s specific seeding instructions. Pete and Gerry found that certain seeds perform better in eggshells than others. Smaller plants, such as oregano, basil, thyme, and flowers, are ideal for starting an eggshell garden. If the plants require sunlight, position the carton where it will receive lots of it, such as on a windowsill.
