D.I.Y. Fridays – Homemade, All-Natural Eggshell Fertilizer

by Nicole Wines


Eggshells washed, dried and ready to crush!

At Raíces EcoCulture, we try to stay conscious about reducing the waste stream.  Whenever possible, we find second uses for materials that would otherwise be looked at as “garbage”.  We upcycle and repurpose as much as we can.  Just like last week’s D.I.Y. post on homemade incense with orange and citrus peels, this week we want to share a tip on using a normally discarded part of a food product used in many kitchens.

Eggshells!  We only eat organic eggs (and local whenever possible) in the Raíces kitchens so we consider our eggshells as an organic source of fertilizer.  Alone, they will not provide plants with all the nutrition necessary to thrive, but they can help boost a few essential and helpful nutrients in the soil, giving gardens and plants a bit of extra support as they grow.

From sfgate.com:

Nutritional Analysis
Eggshells are primarily made out of calcium carbonate, which is the ingredient found in agricultural lime, according to the Master Gardeners of Hamilton County, Tenn. Jeff Gillman, author of “The Truth About Garden Remedies,” did his own small test to determine the nutritional properties of eggshells. He steeped a shell in water for 24 hours and then sent the water to the lab. The lab results found that the eggshell-infused water contained 4 mg of calcium and potassium, as well as very small amounts of phosphorus, magnesium and sodium.”

Calcium helps plants form strong cellular structures.  Plants with calcium deficiencies are often low fruiting/producing plants with stunted growth.  Calcium deficiency is also one of many causes of blossom end rot on tomatoes and peppers.  Just like humans calcium helps plants grow, especially in their younger stages, making eggshell fertilizer especially useful for seedlings and young plants.

Crushing eggshells with mortar and pestle.

Crushing eggshells with mortar and pestle.

We wash, dry, crush and save our eggshells to use in two different ways:

  1. We apply them directly onto the soil, sprinkling them around the base of plants, especially newly transplanted seedlings.  This has the added benefit of repelling slugs (they don’t like the jagged edges) and cabbage moths (the white on the eggshell tricks them into thinking this food source is already claimed by other cabbage moths and they often move on to find a new food source).
  2. Eggshell "tea" or "brew"-Crushed eggshells and water, left to steep for 5-7 days.

    Eggshell “tea” or “brew” – Crushed eggshells soaking in water (5-7 days)

    We make an eggshell “tea” for watering our seedlings and potted plants.  To do this, we soak or steep crushed eggshells for 5-7 days in water, then strain and use the water for watering our seedlings and indoor plants.  We resoak the eggshells two or three times and after the final soaking, we pulverize them in a high powered blender and keep them in the water when watering.  Alternatively, you can pulverize the eggshells first, while still dry.  Then soak the powder for a week in a watering can, watering with that mixture.  We have noticed our indoor plants perk up and our seedlings have little growth spurts when we started doing this.


Crushed Eggshells Saved in Jar

Store extra crushed eggshells in glass jars for future use.

We end up using the second method more often, since we are always nursing seedlings in our indoor growing stations and spring greenhouse and calcium is so important for the development of young plants.  But throughout the winter, we also set aside a portion of our dried, crushed eggshells in a jar for spring and use them around our garden transplants, especially our cabbage.

Have you found eggshells a useful addition to your garden?  Share your experiences in the comment section below.