Homemade Eggshell Powder (Calcium Carbonate)

Do you throw away your eggshells? They are a wonderful addition to your garden in the form of homemade eggshell powder, which doesn’t take long at all to make.

The perfect way to use up kitchen scraps to benefit your garden

We no longer live in our RV full time, which means I am all about planning the garden these days. I’ve really gotten into reading about regenerative farming, and finding ways to replenish the soil, rather than to deplete it.

Creating your own fertilizers and soil amendments is something I am trying to absorb as much information on as I can, before the garden season starts ramping up. Making the fertilizer is something that can take awhile, especially if you aren’t running a breakfast restaurant and are cracking hundreds of eggs each day.

Calcium carbonate is an important mineral for gardens. We often think of fertilizers as containing only NPK – nitrogen, phosphorus and potassium, since that is all that is labeled, but a healthy garden needs a lot more than just those three elements.

Calcium helps to build strong bones in humans, and plants are much the same, it helps to build strong cell walls. Healthier plants are more resistant to disease and to bug infestations. Eggshell pieces also can help to repel certain bugs, if left in small pieces, since they are sharp. Some do say that this does not deter certain bugs though, so you’ll have to try it out for yourself.

If you have chickens, crushing up the eggshells and giving them back to the chickens in the form of a powder will also help them to grow healthier eggs, since laying so many eggs will deplete them of calcium, if they do not take in enough through their diet. But be sure to powder the eggshells before feeding them to your chickens, so that they do not get in the habit of eating eggs right after laying them.

How to create eggshell powder for use in your garden

There are a few different ways to go about making eggshell powder. After making eggs, I usually rinse off the eggs, to ensure the eggs are clean and there is no egg white left behind. If you are only cracking a few eggs at a time, you can then add your eggs to a bag and place them in the freezer. When you build up enough to make the process worth the time, allow them to thaw at room temperature, and then proceed as follows (or you can skip the storage step if you have enough eggshells):

Crush the eggshells and spread out into a thin layer on a baking sheet lined with parchment paper. Place into a preheated over set to 225F (110 C). Bake until dry, approximately 25 minutes. Flipping them half way through helps to dry them out faster.

Remove from oven and allow to cool for 5-10 minutes. Pulverize the eggshells using a mortar and pestle, food processor or coffee grinder. If you are like me, then you usually use the mortar and pestle to grind it to small chunks.

Store in a jar. If fully dry, the eggshell powder should last a very long time. I like to gather my eggshells year round, so that when garden time comes around, I have lots of calcium ready to use.

When I go to use it, I will then decide if I want to grind the eggshells down further, and if so, I will put it in the coffee grinder at that point. The smaller the pieces, the quicker it will break down. Sprinkle a bit around the base of your plants, especially tomatoes and peppers, to help prevent blossom end rot.

What is the shelf life of eggshell powder?

As long as the powder is allowed to fully dry, it should last a year long time (multiple years). I recommend keeping it in an air tight container, away from any moisture, heat or light. If stored well, it should keep for 3+ years.

How much should I add to my plants?

I usually add about one tablespoon into the soil and mix it in when I plant my vegetables, particularly around tomatoes, to prevent blossom end rot. You can add more as the season progresses, as a top dressing, if it seems like your plants could use an extra boost. As the plants grow larger, they will require more nutrients, so if I’m adding it later in the season, I usually add double the amount at that time (two tablespoons).

What plants benefit most from the additional calcium?

Tomatoes, peppers and eggplants benefit from a decent amount of calcium, as it helps to prevent blossom end rot. Leafy greens also benefit from a good dose of calcium. With that being said, all plants need some calcium to grow, so if your soil is depleted, adding extra in will benefit most plants!

And if you are blessed with a huge garden harvest as a result of this, please try some of the following recipes!

• Simple Tomato, Onion and Cucumber Salad
• Tomato, Basil and Spinach Calzones
• Balsamic Chicken with Asparagus and Tomato Basil Mozzarella Salad
• Sun-Dried Tomato Basil Breakfast Skillet
• Sun-Dried Tomato Sauce
• Eggplant Pizzas
• Roasted Red Pepper Eggplant

If you give this homemade eggshell powder a try, please let me know what you think in the comments below. Also be sure to follow me on Facebook and Pinterest so you don’t miss a recipe!