How to Use Eggshells in the Garden—and Why You Should

Before you discard that pile of eggshells after breakfast, consider this: eggshells can provide many benefits to the plants growing in your garden. And with eggs currently such a precious commodity, it's absolutely worthwhile to use every part of them.

Eggshells have a high calcium content that can provide nutrients and add structure to your soil. So, rather than tossing them in the trash, explore these expert-recommended ways you can use eggshells to improve your garden.

Benefits of Eggshells for Plants

Eggshells have many benefits in the garden; here's what they can do.

Increase Calcium Levels

Eggshells consist almost entirely of calcium carbonate—similar to seashells, chalk, and coral. While it can take time, the calcium from eggshells can be worked into the soil to increase its nutrient content. Plants can then utilize the calcium for building cell walls.

Improve Soil Structure

Crushed eggshells can also help improve the texture and structure of some soils. “In my experience, the number one use of eggshells in the garden is in compost,” says horticulturist Jennifer Petritz. “Eggshells do a great job of adding ‘grittiness’ to soil texture and help provide some aeration and lightness to compost.” When the compost is added to the garden soil, the pulverized eggshells remain coarse and granular for some time. 

Deter Pests

Ground eggshells can be difficult for slugs and snails to navigate. For a simple and organic pest control method, try sprinkling roughly crushed eggshells around your plants.

Reduce Soil Acidity

Use eggshells in garden beds where the soil content is too acidic for your plants. The calcium content in eggshells can reduce the acidity of your soil, which is beneficial to plants that prefer soil with a more neutral pH.

Plants That Benefit From Eggshells 

Many types of plants can benefit from eggshells in the garden, including:

• Tomatoes
• Potatoes 
• Peas
• Broccoli
• Cauliflower
• Hostas
• Lungwort
• Daylilies
• Strawberries
• Basil
• Roses
• Hydrangeas
• Ferns
• Ivy

How to Use Eggshells in the Garden

There are a few ways you can use eggshells in the garden.

Replace Seedling Pots

Instead of using plastic seedling pots, rinse out eggshell halves and use them instead. Line them up in an empty egg carton, filling each with a little soil and seeds as directed. When it's time to transplant, simply place the whole eggshell into the soil.

Add to Compost

Rinse, dry, and crush eggshells finely and add them to your compost pile as you would other food scraps where they will decompose over time, says Shelley Cramm, founder of the blog Garden In Delight.

Make a Soil Additive

If you don't have a composter, eggshells can be worked directly into the soil to improve structure and boost calcium content. Rinse, dry, and crush eggshells finely, then mix them into your soil.

Hamper Weeds

Although tedious, eggshells can be used in lieu of mulch to suppress weeds. Rinse, dry, and crush the eggshells, then sprinkle them over the soil.

Tips for Using Eggshells in the Garden

Now that you know how to use eggshells for plants, here are a few more tips to ensure success.. 

Watch out for mosquitoes: “A useful tip in adding eggshells to compost is to lightly crush them first,” says Petritz. “Shells that are left in halves will sometimes collect water and can be breeding areas for mosquitoes. Crushing them first eliminates this problem.”

Test your soil: Perform a soil test before adding eggshells to your soil. This will give you a precise reading on the amount of calcium in the soil already.

Finely crush the eggshells: Eggshells can take a long time to break down, so crushing them helps facilitate the decomposition process when added to compost or soil.