Learn which plants thrive in your Hardiness Zone with our new interactive map!

The Best Ways to Get Calcium From Eggshells for Tomato Plants

By Katherine Bostick ; Updated September 21, 2017
Healthy tomato plants
tomates image by Claudio Calcagno from Fotolia.com

Calcium is essential for proper plant cell development. One way to provide tomato plants with needed calcium is by adding calcium-rich eggshells to the soil. By using the shells in a variety of ways at different stages of the plants’ development, you can help the tomato plants grow stronger. You can even use the eggshells as a pest repellent.

Starting Seedlings

Using eggshell halves provide needed nutrients and calcium to tomato seedlings. Put the eggshell halves in an old egg carton. Add your soil into the eggshell, then add the seeds. Water the plants with leftover water from boiling the eggs for an added calcium boost. The calcium from the eggshell halves will seep into the soil, giving the tomato plants a healthier start. When it is time to replant the tomato seedlings, just crack the shell away from the plant. If you are planting the tomato seedlings in pots, put the broken eggshells at the bottom of the pot. This helps with proper drainage the same as rocks and also adds nutrients to the tomato plant. If not planting the tomato seedlings in pots, crush the eggshells to use in the garden at a later time.

Preparing Crushed Shells

Whole shells take a long time to deteriorate, so it is best to use crushed shells in the soil of the tomato plants. Wash the eggshells, let them dry, put them in a plastic or paper bag, and crush them with a hammer or pastry roller.

Crushed Eggshells in the Garden

When the shells have all been crushed, sprinkle them all over the garden before tilling. When planting the tomatoes, add some crushed eggshells into the hole. Be sure to put some dirt over the crushed eggshells to prevent the tomato plants' roots from touching the crushed eggshells, as the sharp edges can damage the roots. Once the tomatoes have been planted, sprinkle shells all over the top of the soil, and water them with the water the eggs were boiled in to provide even more calcium. The calcium in the crushed eggshells will also help prevent blossom-end rot. Blossom-end rot is a decay that causes tomato plants to have a dry, sunken look.

Pest Prevention

Make sure to put a circle of crushed eggshells around the tomato plants to prevent crawling bugs, such as tomato horn worms, from reaching the tomato plants. Slugs, snails and cutworms will not crawl across the broken shells. The sharp edges of the shells will prove deadly to the crawling bugs.


About the Author


Katherine Bostick has been writing since 1993. She is a freelance writer and has written articles for both the "Spectator" and the "Crossties" newspapers. Bostick writes articles on educational topics, personal essays, health topics, current events and more. Bostick performs copy-editing and book-review services and produces her own local newspaper in South Florida.