Should You Use Eggshells In Compost: 10 Interesting Compelling Factors

Should You Use Eggshells In Compost:  Introduction

Have you ever wondered should you use eggshells in compost? Well, you’ll be delighted to know that eggshells can indeed be a valuable addition to your compost. Not only are they a great source of essential minerals such as calcium, but they also help to balance the pH levels in the compost, creating a nutrient-rich environment for your plants to thrive. So, instead of throwing those eggshells away, why not give them a new purpose and contribute to the health of your garden? Discover the benefits of incorporating eggshells into your composting routine and unlock the secret to healthier, more fruitful plants.

Table of Contents

Check Out Our Recommended Composting Products on Amazon Right Here!

Benefits of Eggshells in Compost

Improves soil structure

One of the major benefits of adding eggshells to compost is that it improves the soil structure. Eggshells contain calcium carbonate, which when broken down, helps to create a crumbly texture in the soil. This allows for better water drainage and aeration, which is essential for the roots of plants to grow and thrive.

Adds essential nutrients

Another advantage of using eggshells in compost is that they provide essential nutrients to the soil. Eggshells are rich in nutrients like calcium, magnesium, and potassium, which are all vital for the growth and development of plants. By adding eggshells to your compost pile, you are enriching the soil with these nutrients, ensuring that your plants have everything they need to flourish.

Balances pH levels

Eggshells also play a significant role in balancing the pH levels of the soil. The calcium carbonate present in eggshells acts as a natural buffer, helping to maintain a neutral pH level in the soil. This is crucial because certain plants require a specific pH level to grow properly. By incorporating eggshells into your compost, you can create a more favorable environment for a wide range of plants.

Should You Use Eggshells In Compost:  Preparation for Composting

Rinse and dry the eggshells

Before adding eggshells to your compost pile, it is essential to rinse them thoroughly to remove any residual egg. This is important because any remaining egg on the shells can attract pests and create unpleasant odors. Once the shells are rinsed, allow them to dry before crushing them. Drying the shells helps to prevent mold or mildew growth in your compost pile.

Crush the eggshells

To facilitate the decomposition process and ensure that the nutrients from the eggshells are more readily available to plants, it is recommended to crush the eggshells before adding them to the compost pile. Crushing the shells into smaller pieces increases the surface area, allowing for faster breakdown and nutrient release. You can use a mortar and pestle or simply crush them with your hands.

Are Eggshells Good For Compost?

Check Out Our Recommended Composting Products on Amazon Right Here!

Understanding Composting

What is composting?

Composting is a natural process of recycling organic waste materials into nutrient-rich soil. It involves the decomposition of various organic matter, such as kitchen scraps, yard waste, and, of course, eggshells. This decomposition process is carried out by microorganisms, including bacteria and fungi, that break down the organic matter into simpler forms that plants can absorb and utilize.

Importance of composting

Composting is beneficial for both the environment and gardeners. It helps divert organic waste from landfills, reducing the production of harmful methane gas. By composting, you can also reduce the need for synthetic fertilizers, which can be detrimental to the environment. Compost improves soil fertility, promotes healthier plant growth, conserves water, and enhances overall soil structure.

Components of a compost pile

Creating a compost pile requires a mixture of green and brown materials. Green materials include nitrogen-rich items like grass clippings, vegetable scraps, and coffee grounds. Brown materials, on the other hand, are carbon-rich materials like dried leaves, twigs, and cardboard. Eggshells fall into the brown category because of their high carbon content. A balanced mix of green and brown materials promotes proper decomposition and the development of nutrient-rich compost.

Chemical Composition of Eggshells

Calcium carbonate

The main chemical component of eggshells is calcium carbonate, which makes up about 95% of the shell’s composition. Calcium carbonate is an excellent source of calcium for plants, which is an essential nutrient required for plant growth, cell division, and root development. By adding eggshells to your compost, you are providing a natural and easily accessible source of calcium for your plants.

Trace minerals

Eggshells also contain trace minerals like magnesium, which contribute to the overall health and vitality of plants. These trace minerals are important for various plant functions, including photosynthesis, enzyme activity, and the production of chlorophyll. Incorporating eggshells into your compost helps to create an optimal environment for plants while ensuring they receive a diverse range of nutrients.


While present in smaller amounts, eggshells also contain small traces of protein. This protein content is beneficial for the microorganisms involved in the composting process. Microorganisms require nitrogen-rich materials like proteins to carry out the decomposition process efficiently. By providing a small amount of protein, eggshells support the activity of these microorganisms, resulting in faster breakdown and nutrient release.

Are Eggshells Good For Compost?

Should You Use Eggshells In Compost:  Decomposition of Eggshells

Time required for decomposition

The decomposition of eggshells can vary depending on various factors such as temperature, moisture levels, and the size of the eggshell pieces. On average, it takes about six to twelve months for eggshells to fully decompose in a compost pile. However, it’s important to note that eggshells may not break down completely and may still retain some fragments. These fragments can still provide beneficial nutrients to the soil as they slowly breakdown over time.

Factors affecting decomposition process

Several factors can influence the decomposition process of eggshells in compost. Moisture is essential for the breakdown of organic matter, including eggshells. Maintaining a proper balance of moisture in your compost pile ensures that the microorganisms responsible for decomposition can thrive. Temperature also plays a role, as higher temperatures can accelerate decomposition. Additionally, regularly turning your compost pile promotes aeration, which speeds up the decomposition process.

Adding Eggshells to Compost

Incorporating directly into compost pile

The simplest way to add eggshells to your compost is to incorporate them directly into the compost pile. Make sure to crush the eggshells beforehand to speed up decomposition. Mix the crushed eggshells with other organic matter, such as kitchen scraps and yard waste, in layers. This helps to create a balanced compost pile and ensures that the nutrients from the eggshells are evenly distributed.

Crushing before adding

As mentioned earlier, crushing eggshells before adding them to your compost pile is highly recommended. This not only aids in decomposition but also helps to prevent the shells from attracting pests. Crushed eggshells have a larger surface area, allowing for faster breakdown and nutrient release. They also blend more easily with other compost materials, promoting a homogeneous mixture.

Layering eggshells

Another method of incorporating eggshells into your compost is layering. Rather than crushing the eggshells, you can sprinkle them in layers throughout your compost pile. This technique ensures that the nutrients from the eggshells are distributed more evenly and prevents clumping. However, it’s important to note that layering eggshells may result in slower decomposition compared to crushed eggshells.

Are Eggshells Good For Compost?

Tips for Composting Eggshells

Avoid adding shells from raw eggs

When composting eggshells, it is best to avoid adding shells from raw eggs. Raw eggshells can carry harmful bacteria like Salmonella, which can contaminate your compost pile. To eliminate this risk, make sure to rinse the eggs thoroughly and only add shells from cooked or pasteurized eggs.

Washing off residual egg

To prevent attracting pests and minimizing odors in your compost pile, it is essential to wash off any residual egg from the shells before composting. Rinse the shells under running water, making sure to remove any sticky residue. Once the shells are clean, allow them to dry before crushing or adding them to your compost pile.

Controlling pests and odors

To deter pests and control odors in your compost pile, you can take a few additional measures. Mixing in garden lime or adding a layer of carbon-rich materials like dried leaves can help neutralize odors. It’s also advisable to cover your compost pile with a breathable compost cover to prevent easy access for pests. Regularly turning your compost pile can further deter pests and promote proper aeration.

Should You Use Eggshells In Compost:  Composting Dos and Don’ts

Do include other organic materials

To create a balanced and nutrient-rich compost, it is important to include a variety of organic materials in addition to eggshells. This can include kitchen scraps, coffee grounds, yard waste, and dried leaves. The diverse mix of materials ensures a wide range of nutrients and promotes a healthy microbial population in your compost pile.

Don’t add oily or fatty substances

While many organic materials can be composted, it is advisable to avoid adding oily or fatty substances to your compost pile. These substances can create an imbalance in the compost and slow down the decomposition process. Additionally, they can attract pests and create unpleasant odors. It’s best to dispose of oily or fatty substances through other means, such as recycling or proper waste disposal.

Avoid using animal products in compost

To maintain a healthy compost pile, it is generally recommended to avoid using animal products such as meat, bones, dairy products, and pet waste. Animal products can introduce pathogens and attract unwanted pests. Stick to plant-based materials, like vegetable scraps and yard waste, to ensure a safe and effective composting process.

Are Eggshells Good For Compost?

Alternative Uses for Eggshells

Gardening uses

Besides being a valuable addition to compost, eggshells have other uses in the garden. You can crush and sprinkle eggshells around the base of plants to deter slugs and snails, as their sharp edges can be a deterrent to these pests. Additionally, finely ground eggshells can be used as a natural and calcium-rich soil amendment for calcium-deficient plants like tomatoes and peppers.

Pest control

Eggshells can also be used as a natural pest control method. Crushed eggshells can be strategically placed around flower beds or vegetable gardens to repel pests like ants, caterpillars, and beetles. The jagged texture of the eggshells acts as a barrier, discouraging pests from approaching the plants.

Household cleaning

Eggshells can be repurposed as a cleaning agent in your household. Crushed eggshells mixed with a small amount of soapy water can be used as a gentle abrasive to clean pots, pans, and other kitchen utensils. The abrasive nature of the eggshells helps to remove stubborn stains and residue without scratching the surfaces.

Should You Use Eggshells In Compost:  Conclusion


In conclusion, eggshells are indeed good for compost and offer numerous benefits to gardeners. They improve soil structure, provide essential nutrients, and balance pH levels. Proper preparation, such as rinsing and crushing the shells, ensures optimal breakdown and nutrient release. Adding eggshells to compost is a simple and effective way to utilize this kitchen waste and create nutrient-rich soil for your plants. Remember to follow composting guidelines, avoid adding shells from raw eggs, and explore alternative uses for eggshells in gardening and household applications. By incorporating eggshells into your composting routine, you are not only reducing waste but also nurturing the health and vitality of your gardens. So go ahead, save those eggshells, and watch your plants thrive!


Are eggshells beneficial for compost?

Yes, eggshells are beneficial for compost as they are rich in calcium, a nutrient that helps plants develop strong cellular structure. When added to compost, eggshells break down over time and enrich the soil with calcium, which is particularly beneficial for growing vegetables like tomatoes and peppers that require higher calcium levels to prevent blossom end rot. However, they should be crushed into smaller pieces to speed up the decomposition process.

How do eggshells decompose in compost?

Eggshells decompose in compost through the activity of microorganisms that break down organic matter. As eggshells are made mostly of calcium carbonate, a mineral compound that breaks down slowly, they decompose at a slower rate than other organic materials. Crushing the eggshells into smaller pieces can help accelerate their decomposition by increasing their surface area and making them more accessible to the microbes in the compost.

Can eggshells in compost attract pests?

Eggshells themselves are unlikely to attract pests to compost as long as they are rinsed and free from egg residue. The protein and fat remnants in egg residue can attract rodents and insects. Therefore, it’s important to ensure that the shells are clean before adding them to your compost pile. Additionally, burying the shells in the center of the compost pile can help minimize the attraction of pests.

Is there a risk of salmonella with eggshells in compost?

There is a potential risk of salmonella contamination with eggshells in compost if they are not properly handled. Salmonella bacteria can be present on the outside of eggshells. To minimize this risk, eggshells should be rinsed before being added to the compost. The heat generated by a well-maintained compost pile can also help kill salmonella bacteria, making the compost safe to use in your garden.

Should eggshells be crushed before adding them to compost?

Crushing eggshells before adding them to compost is recommended because it helps speed up the decomposition process. Whole eggshells can take much longer to break down, while crushed shells have more surface area for soil microbes to work on, allowing the calcium content to be released into the compost more quickly. You can crush them by hand, with a mortar and pestle, or by drying and crumbling them.

How long do eggshells take to decompose in compost?

The time it takes for eggshells to decompose in compost can vary widely, typically ranging from a few months to a couple of years. This timeline can be influenced by factors such as the size of the eggshell pieces, the conditions of the compost pile, and the balance of materials in the compost. Finely crushed shells in a well-managed, hot compost pile will decompose much faster than whole shells in a cooler, less active pile.

Do eggshells change the pH of compost?

Eggshells are alkaline in nature, so they can potentially raise the pH of your compost if added in large quantities. However, in typical household composting, the amount of eggshells added is usually not sufficient to significantly alter the pH balance. If you’re concerned about pH levels, it’s advisable to monitor your compost’s pH and add eggshells in moderation.

What is the best way to add eggshells to compost?

The best way to add eggshells to compost is to rinse them to remove any egg residue, dry them, and then crush them into smaller pieces. This preparation ensures that they break down more efficiently and do not attract pests. The crushed eggshells can then be mixed into the middle of the compost pile, which helps in quicker integration with other composting materials.

Can eggshells be used in worm composting systems?

Eggshells can be used in worm composting systems, or vermicomposting, as they provide grit to help worms digest their food. However, it’s essential to crush the eggshells into a fine powder before adding them to a worm bin to avoid harming the worms. The calcium in the shells also benefits the overall health of the worms and contributes to the nutrient content of the vermicompost.

Are there any types of compost systems where eggshells should not be used?

Most compost systems can benefit from the addition of eggshells. However, in closed composting systems with limited aeration or in systems that primarily deal with acidic materials, adding a large number of eggshells might disrupt the balance and slow down the composting process. It’s important to consider the specific requirements and balance of your composting system when deciding whether to add eggshells.


Check Out Our Recommended Composting Products on Amazon Right Here!

Sharron Nixon

Hi there! I'm Sharron, the face behind Composting Guru. I'm passionate about helping you discover and unlock the earth's secret recipe - composting. With our curated content, expert advice, and top-tier tools, I'm here to guide you in mastering the art of composting. Whether you're searching for the perfect composter or seeking tips on creating nutrient-rich compost, you've come to the right place. Together, we'll transform your waste into garden gold. Join me on this journey as we dive deep into the world of composting and unlock its true potential. Let's make the Earth thrive with Composting Guru!

More to Explore

Should Compost Be Rained On?

Discover why rain is beneficial for composting and how it aids in the decomposition process. Learn about moisture levels, benefits of rainwater, drawbacks of excessive rain, and strategies to control moisture. Create nutrient-rich soil for your garden with the help of rainwater!