I love cooking with eggs, and so I always have lots of eggshells. Can I add them to my compost pile?
Short Answer: They Can Be Added to Your Compost Pile
You can include eggshells among the items that you can put in your compost bin. Eggshells can provide soil and compost with a good amount of calcium, along with some magnesium and potassium. These nutrients are important for healthy plant growth.
However, do not compost whole eggs. Whole eggs will attract rats, raccoons, skunks, or other animals to your composting area.
Composition
Eggshells are made up of 95% to 97% calcium carbonate. The shell has a very thin outer layer called the bloom or cuticle that helps keep bacteria and dust out. As the embryo grows, calcium from the eggshell helps it build strong bones.
Why Eggshells Are Helpful for Your Compost
Eggshells are high in calcium. This macronutrient is essential for the growth and development of plants.
Calcium from eggshells helps plants build cell walls faster, so they can grow more quickly. It can also help decrease the risk of blossom end rot.
How Long Does It Take to Break Down?
Eggshells can take over a year to break down. If the shell is not broken up, the calcium remains in the shell itself . That means plants cannot access it. If you grind the shells before adding them to your compost bin, they break down much faster and the calcium is released into the soil.
Are Eggshell Pieces in My Compost a Problem?
Sometimes, pieces of eggshells remain when composting is done. That is not a problem, but some people find it ugly.
If you grind the shells before putting them into the compost bin, this won’t happen. If you don’t have access to a grinder, let the shells dry out for a few days or put them into a hot oven for a while. It is then easier to crush the shells into small pieces that aren’t visible in soil.
Why Should I Grind Up My Eggshells?
Grinding eggshells before adding them to your compost speeds up the breakdown process. Its nutrients are added to the soil much faster.
Tests have shown that finely ground eggshells are as good as or better than pure calcium and agricultural lime at correcting acidic soil.
You can use a coffee grinder to powder eggshells. Don’t use an expensive grinder, and consider getting a cheap grinder for only this purpose. You don’t want eggshell powder in your coffee!
You don’t even have to add your ground eggshells to the compost bin. If you prefer, you can spread them directly onto the soil in your garden.
Is There Danger of Salmonella?
There is always a risk of contaminated food. Undercooked eggs can pose a risk of salmonella. But there are safeguards in place.
Farmers have to wash their eggs before packaging them to reduce the risk of salmonella. And thoroughly cooking eggs before consuming them kills salmonella bacteria.
During the composting process, temperatures can rise to 140 to 160 degrees Fahrenheit, which will kill many pathogens, including salmonella.
Usually, eggshells make up only a small percentage of the compost. The risk of salmonella is close to zero.
What About Adding Eggshells as a Soil Amendment?
Eggshells need to be broken down to be of value to the soil and plants.
Eggshells placed in the soil do not break down easily. They are not of much benefit to the plants.
