Can Eggshells Be Composted & Used In Your Garden?

The part that we eat is a source of protein and proteins are generally a no-no when it comes to composting, but what about the shell?

Are eggshells compostable? The short answer is yes, eggshells are compostable, but it is important to understand how it will affect your gardening before incorporating them into your compost pile.

Maybe you are just starting out in the adventurous world of composting and are trying to decide what food scraps will be safe to add to your growing pile.

Related | What Is Composting?

Or maybe you have an established compost pile but are wondering how to make it more beneficial for your plants. One food byproduct that may give you pause is eggshells.

The following article will explain how they can be a beneficial addition, how to prepare the eggshells for use in compost, and which plants will benefit as well as which may actually be harmed.

We will also address what the risks are, if any, to using them.

Are Eggshells Good For Plants?

Eggshells are mainly made of a compound called calcium carbonate along with a small amount of protein and other nutrients. As this compound breaks down, calcium will be free and can then be used to help certain plants thrive in the garden.

Eggshells will not break down quickly like other organic matter, such as bread, so you will most likely notice them when it is time to use your compost.

The slow breakdown of the shells is not necessarily a bad thing as it means the nutrients from the shells will be released throughout the growing season.

Including eggshells in your compost can help prevent blossom-end rot, which is a common headache for gardeners. It is identified by a rotten spot found at the end of fruit as it is on the verge of ripening.

Blossom-end Rot Tomato Plant

Blossom-end rot occurs on the fruit of plants that have a chemical imbalance, and the nutrients in eggshells help to restore this balance.

Besides providing nutrients for plants, eggshells can be used as deterrents for slugs and other crawling pests. The edges are sharp to these soft-bodied creatures and will create tiny tears in their skin through which they dehydrate and die.

Finally, eggshells can assist in slightly increasing the pH of the soil. This is beneficial to plants that do not like acidic soil but prefer a more basic soil.

Does Composting Kill Salmonella?

It is well known that eggs can contain the bacteria Salmonella.

Can they contaminate your garden? If present in your compost, most strains will be killed when the temperature of the compost reaches at least 140 degrees Fahrenheit.

While eggshells have the potential to introduce Salmonella into your compost pile, most contamination problems are caused by animal waste products.

Covering your compost pile can help prevent critters from contaminating it with any bacteria-containing waste.

What Plants Like Eggshells?

Plants that are prone to blossom-end rot, fed on by soft-bodied creepy crawlies, and whose roots take up a lot of calcium will enjoy the addition of eggshells in compost.

Cucumber, eggplant, pepper, and tomato plants are just a few of the kitchen garden plants that tend to succumb to blossom-end rot.

what plants like eggshells

Plants such as spinach, lettuce, broccoli, and marigolds often fall prey to snails and slugs. Some ornamental plants such as lilacs, clematis, forsythia, butterfly bushes, and roses will also benefit from composted eggshells.

Just be sure to know the pH of your soil before adding eggshells to make sure the pH does not move out of range for the specific plant(s) you are treating.

Since eggshells tend to make the soil slightly more basic, you should not include them in compost that will be used around that prefer an acidic soil like azaleas and rhododendrons.

How To Prepare Eggshells For Composting

It is generally recommended that eggs not be included in the compost pile. Not only do they tend to smell while decomposing, but they also are more likely to attract pests to your pile. Rinsing the eggshell out is not necessary but certainly would not hurt.

Related | Does Compost Smell?

Eggshells can be added to compost whole and will still break down to release their nutrients. However, breaking them up into small pieces will speed up the decomposition process and allow the eggs to release their nutrients more quickly. They can also be ground into a fine powder to increase areal coverage.

In Summary

Adding eggshells to your compost pile is a cost-effective way to protect and boost your plants. Not only do they provide protection from certain pests, but they also give plants nutrients needed to help protect against certain diseases and fungi, and help strengthen the plant’s cells.

The addition of eggshells to your compost can increase your garden’s productivity and save you the cost of store-bought fertilizers. And let’s not forget the benefit of using natural materials over synthetic, lab-made chemicals.

Just be sure to check each plant’s soil preferences before adding eggshell-containing compost to the surrounding soil.

About Justin Micheal

Justin has always loved gardening and caring for the outdoor spaces in his grandmother's backyard. He believes everyone can enjoy the space available to them, no matter how big or small. On Backyard Digs, he shares everything he's learned about growing a successful garden and maintaining and improving the landscape of a backyard.