Are Eggshells Good for Soil?

Consider using finely crushed eggshells to improve soil quality.

Before you toss eggshells into the trash can, consider recycling them. There is some truth to the theory that crushed eggshells are good for garden soil. The key to their effectiveness may be the degree to which the shells are crushed.

Theories/Speculation

Some home gardeners add eggshells to the garden, believing the shells will enrich the soil with calcium. Crushed eggshells can also to repel hungry slugs that may otherwise feast on your plants, according to Anita Baxley in "Mother Earth News."

The Facts

Eggshells crushed by hand or only coarsely ground have been found to be a less than effective soil amendment, notes the Alabama Cooperative Extension. However, shells that were finely ground into powder may significantly improve calcium levels and raise soil's pH level.

Considerations

Dry empty eggshells in the oven on the lowest temperature to make crushing them easier. Mix crushed shells into the soil. Consider adding coffee grounds to the crushed eggshells; doing so may improve nitrogen and phosphorous levels in the soil.

References

• Alabama Cooperative Extension System: Crushed Eggshells in the Soil
• Apartment Therapy: Plant Therapy: Simple Plant Food, for Free
• Mother Earth News: Country Lore: Foil Sluggs with Eggshells