How to Use Eggshells as Fertilizer for Healthier Tomato Plants

One of the most important lessons I learned in my gardening journey is that tomatoes need calcium—and one of the simplest, most natural ways to provide it is with eggshells. In this post, I’ll show you how eggshells can improve soil health, prevent blossom end rot, and help your tomato plants thrive!

Like most gardeners, my journey into growing my own food started with the classic crop—tomatoes. When I lived down South, growing tomatoes was effortless. Year after year, my plants thrived, producing an abundance of fruit to enjoy fresh and preserve for the colder months. However, after moving to Wisconsin, everything changed. Despite my best efforts, my tomato plants followed the same frustrating pattern—growing strong and producing green fruit, only to suddenly wilt and die. Three years. Zero tomatoes.

Determined to turn things around, I took a break in year four to research, experiment, and rethink my gardening approach. I implemented new strategies, focusing on soil health and natural amendments. By year five, the results were astonishing—I grew over 500 pounds of tomatoes in a smaller space, with plants thriving well into October!

Hands-On Research and Experiments

As part of my research that year, I spent countless hours reading every comment I could find in gardening forums and social media groups, soaking up advice from seasoned gardeners.

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But research alone wasn’t enough—I needed to see what actually worked in my own garden. So, I put different techniques to the test, experimenting with various methods to determine which ones produced the best results. Through trial and error, I discovered what truly made a difference in growing healthy, productive tomato plants.

Why Eggshells Are Great for Tomato Plants

Through research and hands-on experience, I discovered that maintaining balanced, nutrient-rich soil is key to healthy tomato plants. Instead of store-bought fertilizers, I used natural amendments like eggshells and compost. The result? A thriving, chemical-free garden!

• Rich In Calcium: Tomatoes need calcium to build strong cell walls. Without enough, they develop a disease called blossom end rot, which causes black, sunken spots on the fruit
• Improves soil structure and drainage: Crushed eggshells add texture and space within the soil, improving aeration and allowing roots to spread more easily
• Provides slow-release nutrients as they break down – Eggshells are not immediately available to plants; they break down slowly, releasing calcium over time. For faster results, grind them into a fine powder before adding them to the soil. This ensures tomatoes get the nutrients they need sooner
• Helps deter certain pests, like slugs and snails: eggshells are sharp and provide jagged edges, making it uncomfortable and even harmful to soft-bodied creatures

Step-by-Step Guide to Making Eggshell Fertilizer

1. Collect and Prepare Eggshells

• Save eggshells from daily cooking
• Rinse them to remove any egg residue

2. Dry the Eggshells

• Let them air dry, or place them in a low-temperature oven for quicker drying (200°F oven for 1-2 hours works great)
• 💡 Pro Tip: line your baking sheet with parchment paper first! Otherwise, if the eggs aren’t washed perfectly (like the egg on the far left in this photo), they will stick to the pan and become nearly impossible to remove (I had to throw my pan away!)

3. Grind the Eggshells

• Use a blender, food processor, or mortar and pestle to crush them into small pieces or powder

4. Store for Later Use

• Keep the crushed eggshells in an airtight container for convenience

How to Use Eggshell Fertilizer in the Garden

Adding crushed eggshells to your tomato garden can be done before you plant the tomato plants and during the growing process.

1. Mixing into the Soil

• Sprinkle crushed eggshells into the soil before planting tomatoes
• Work them into the top few inches of soil around established plants
• If adding to already established plants, sprinkle the eggshells as close to the roots/soil as possible and then lightly water so the eggshells will become absorbed into the soil

2. Adding to Compost

• Mix eggshells into compost to enrich the soil with calcium over time
• If you have a compost pile, you can skip the process of grinding up the eggshells, just throw in the cracked eggshells and overtime they will break down, particularly when you turn your compost pile

Other Garden Uses for Eggshells

• Pest Control: Scatter larger eggshell pieces around plants to deter slugs and snails
• Seed Starters: Use eggshell halves as biodegradable seedling pots
• Enriching Other Plants: Peppers, eggplants, and other calcium-loving plants also benefit

My Real Life Experience

I’m thrilled to share that my tomatoes, which I started from seed indoors, thrived beyond my expectations! After four years of failed attempts, I was astonished by how much healthier and more productive my plants became with these simple changes—especially incorporating eggshells into my gardening routine. Now I can make endless jars of The Best Spicy Salsa Recipe for Canning!

If you’ve struggled with growing tomatoes or want to boost your harvest naturally, why not give eggshell fertilizer a try? Start saving your eggshells today, and let me know how it works for you! Have questions or gardening tips of your own? Drop a comment below—I’d love to hear from you!