Crushed eggshells add valuable calcium to soil. Calcium is essential for cell growth in all plants and helps plants build healthy cell walls. Calcium is especially important for fast growing plants like arugula, cucumbers, baby carrots, and radishes because they quickly deplete the surrounding soil of calcium. Without calcium, plants will grow slowly, and some vegetables like tomatoes and squash will develop end rot.

Why add crushed eggshells to your garden?

Eggshells will also reduce the acidity of your soil and help to aerate it. Aeration creates small holes in the soil, allowing  air, water and nutrients to penetrate the plant and tree roots. With aerated soil, roots grow deeply, producing stronger and more vibrant plants and trees.

Eggshells should be washed before you place them in a compose or into your garden.  Washing eggshells will not lure animals to your garden and will reduce the slight risk of disease caused by raw eggs. Make sure you crush them before you add them to the soil. Eggshells that are not crushed will break down very slowly.

How to use egg shells in the garden:

  • Instead of throwing eggshells away, put them in the bottom of plant pots instead of stones. Eggshells are much lighter than stones and they are a great source of of nutrition.
  • Place eggshells in a circle on top of the ground surface around tender plant stems such as peppers, tomatoes, broccoli, cabbage to deter slugs and cutworms.
  • Place eggshells in the soil near tomatoes. Calcium is very useful to tomatoes, squash, peppers and other fast growing plants because the extra calcium will help prevent blossom end rot.
  • Add a layer of crushed shells mixed with leaves and compost to the bottom of a hole to help newly planted plants and trees thrive.

Can eggshells be used along with coffee grounds?

Yes. Eggshells provide calcium to your garden while coffee grounds provide a high content of nitrogen to your garden. Calcium and nitrogen supplements (eggshells and coffee grounds) will help keep your garden soil rich with nutrients and your plants healthy. We source our coffee grounds from Starbucks Grounds for Your Garden.

Eggshells for natural pest control

Crushed eggshells can also be used in the garden as a natural solution to ward off pests like slugs, snails, cutworms and other crawling pests. Crushed eggshells work by making several small cuts in the pests as the bugs attempt to crawl over them. The bugs then dehydrate and die from these cuts. Larger animals like deer will stay away from eggshells because they hate the smell of the albumen.

Using eggshells in your garden should be a year-round effort. Add them to your soil or compost bin regularly. Eggshells break down slowly. Sometimes it takes several months to be completely broken down into the soil and absorbed by a plant’s roots.

Use eggshells as seed starters

Empty, clean eggshells can be used as seed starters. First, fill an egg carton with empty, rinsed eggshell halves and poke a hole in each one for drainage. Then add potting soil, organic compost, and 2 to 3 seeds to each shell. When the seedlings are big enough for transplanting outside, plant the seedling and eggshell directly into the soil. Our favorite seed supplier is Baker Creek Heirloom Seeds.

Eggshells, aeration, and beneficial bugs

Eggshells help to aerate the soil by loosening the soil and creating little pockets of air. The pockets of air allows the for beneficial insects to live and thrive. Beneficial insects are an important ingredient to a healthy garden. They supply the soil with nutrients,

The most common beneficial insects are:

  • Aphid midges
    • Aphid midges’ primary food is the aphid.
    • Attract them to your garden with dill.
  • Bees
    • Bees are beneficial because they pollinate most of our fruits and vegetables.
    • Attract bees with flowering trees, and plants.
  • Braconid Wasp
    • Adult Braconid Wasps are friendly to humans. They do not sting unless provoked.
    • They eat aphids, codling moths, garden webworms and many different caterpillars, beetles, and flies.
    • Attract them to your garden with nectar plants that have small flowers, and with dill, parsley, and wild carrots.
  • Green lacewigs
    • Green lacewigs will eat aphids, whiteflies, leafhoppers, mealybugs.
    • Attract them to your garden with dill, angelica, or coriander.
  • Ground beetle
    • Ground beetles are nocturnal and feed at night.
    • They eat slugs, snails, cutworms, cabbage maggots, and caterpillars.
    • Attract ground beetles with perennials or a compost pile.
  • Ladybugs
    • Ladybugs are beneficial because they eat a lot of garden pests.
    • One ladybug can eat on up to 50 aphids per day, and 50,000 in their lifetime.
    • Ladybugs also enjoy eating mealy worms, leafhoppers, and mites.
    • Attract ladybugs to your garden by planting dill and fennel. As a double bonus, when you plant dill, you’ll also attract rare butterflies.
  • Praying Mantis
    • Praying Mantis love to eat caterpillars, moths, beetles, and crickets.
    • Attract them to your garden with shrubs, dill, and marigolds.
  • Spined soldier bugs
    • Spined soldier bugs will eat caterpillars and beetle larvae.
    • They need a lot of water and might suck on your plants to satisfy their water needs. Given this, it is important to keep your plants well watered.
  • Tachinid Fly
    • Tachinid flies are attracted to dill, parsley, clover, and herbs.
    • Their attraction to flowers will help the bees pollinate your garden.
    • This fly kills several bugs, including
      • gypsy moths
      • cabbage loopers
      • Japanese beetles,
      • armyworms
      • cutworms
      • sawflies
      • codling moths
      • peach twig borers
      • pink bollworms,
      • tent caterpillars, and
      • squash bugs.