Eggshells in the Organic Garden

Posted by Jamie McIntosh Jun 9, 2009

Sometimes I get questions from gardeners about adding eggshells to the compost bin. Yes, eggshells are appropriate compost ingredients, but they break down very slowly. If you plan to add eggshells to the compost bin, you can grind them up with a coffee bean grinder or blender first to achieve uniform, crumbly compost. Gardeners with a compost worm bin can use eggshells to provide necessary grit and calcium to the red worms.

Eggs and eggshells have other uses in the organic garden. If you prepare boiled eggs, save the cooking water to use in the garden to revive tired plants. The calcium and other micronutrients are beneficial to both vegetables and ornamental plants. Tomato plants especially need the calcium boost to prevent blossom end rot, so add eggshells directly to the planting hole.

The raspy edges of broken eggshells repel pests from the lowly gastropod to housecats. Neither slugs, snails, nor cats wish to transverse the jagged barrier a few crushed eggshells provide.