Calcium Fertilizer from Crushed Eggshells

Finely ground eggshells provide a natural, slow-release source of calcium for the garden.

Because eggshells are made mostly of calcium carbonate and decompose slowly, they are most effective when ground into a fine powder and incorporated into soil in the fall, over winter, or several weeks to months before spring planting. Alternatively, add crushed eggshells to compost year-round. 

Plants that benefit from added calcium: tomatoes, peppers, eggplants, broccoli, cabbage, cauliflower, lettuce & leafy greens, celery, squash, zucchini.

Herbs that tolerate or prefer lime-rich soil which naturally contain calcium: sage, thyme, rosemary, and oregano

Equipment

• Electric coffee grinder

• An old spice jar with shaker top and cap--wash and dry thoroughly.

Ingredients

Half-dozen to dozen washed and thoroughly dried eggshells

Instructions

• Wash and dry eggshells thoroughly

• Grind into a fine powder (a couple of egg shells at a time)

• Fill the spice jar and cap securely

• Store in a cool dry place until ready to use

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Refrences: Garden MythBusters: The dos and don’ts of natural remedies | Over the Garden Fence | Illinois Extension | Illinois, https://extension.umd.edu/resources, Chalky soils: plants for | RHS Advice, What Plants Like Calcium and How to Add It - ScienceInsights, 30 Plants That Thrive in Alkaline Soil (pH 7.5–8.5), From Lavender to Lilac - Blooming Expert