How to Use Eggshells to Fertilize Your Garden?

Whether you’re baking cake or whipping up an omelet, you’re left with a few eggshells that you usually throw away.

This time, how about doing a little experiment?

Keep the eggshells and use them as fertilizer for your garden! Below I cover the ways you can use eggshells to fertilize your plants and the benefits your plants stand to gain by using eggshells as fertilizer.

Preparing the Eggshells for Your Garden

There are two ways in which you can use eggshells for your garden plants — steeping them in water or crushing them.

Crushing Eggshells

Take a few dry and clean eggshells and crush them in a mortar with pestle. Alternatively, you can place them in a food processor and create an eggshell powder.

Depending on how small or large the eggshells are after crushing them, I recommend that you add larger particles to the soil in autumn as it can take a long time for eggshells to decompose.

Powdered eggshells can be added even in spring or summer. You can mix powdered eggshells into the soil when planting your garden.

I honestly prefer the powdered version to the crushed one. I simply don’t like the sight of crushed eggshells on the soil of my garden.

Some say crushed eggs create an interesting contrasting element in the garden, but I fail to see its aesthetic appeal, so I stick to the powdered version.

Steeping Eggshells in Water

Another method that’s a bit longer than simply just crushing eggshells is to steep them in water. Here’s how to do it:

  • Take between 10 to 20 eggshells (make sure they’re dry and clean)
  • Boil a gallon of water
  • Add the eggshells to the water and let sit overnight or for up to 24 hours
  • Strain the water

The resulting ‘eggshell concentrate’ can be used directly to water your plants.

Now that you know how to use eggshells to fertilize your garden plants, let’s see the benefits of doing so.

Benefits of Using Eggshells as Plant Fertilizer

We all know that eggshells are a source of calcium carbonate. Apart from this, the eggshell concentrate resulting from steeping eggshells in water also contains trace amounts of potassium, phosphorus, magnesium and sodium.

Gardeners who regularly use eggshells in their gardens claim that both the eggshell concoction and crushed eggshells can have the following benefits:

  • Aids plants in developing a strong cellular structure thanks to the calcium content of the eggshells
  • Reduces the incidence of blossom end rot in plants such as tomatoes
  • Prevents dark spots forming on the bottom of fruits in fruiting plants
  • Can deter some unwanted pests in your garden

In short, eggshells can act as a fertilizer for your plants, but it’s important that they’re not a cure-all, solve-all fertilizer.

Eggshell fertilizer simply offers a calcium boost to plants, but it’s not a complete fertilizer and should not be used as a substitute for a balanced fertilizer.

Which Plants Like Eggshells?

Eggshells can potentially be most beneficial in your vegetable garden. Here are the veggies that will enjoy the extra boost of calcium provided by eggshells:

  • Tomatoes
  • Peppers
  • Cauliflower
  • Broccoli
  • Swiss chard
  • Spinach
  • Eggplants
  • Amaranth

Generally, “food-growing plants” will require more calcium compared to regular plants, so they’re the ones that would benefit most from this home-made fertilizer.

How Often to Use Eggshells for Your Plants?

Assuming that you do have a steady supply of eggshells in your household (I, for one, don’t eat eggs very often), you can use them at varying frequency depending on how you plan on using it.

Crushed eggshells take time to decompose, so sprinkling them onto or working them into the soil is best carried out in autumn, so it will have time to decompose.

When used in powdered form, you can use them whenever you’re repotting your plants or whenever you want to give your plants a little boost.

You can use eggshell tea weekly to water your plants or garden. Ultimately, the way your plants respond to this home-made fertilizer will also have a say in how often you can or should use eggshells in your garden.

But generally, because crushed eggshells take a longer time to decompose, you’ll need to use them less often than powdered or steeped eggshells.

Can You Repel Slugs with Eggshells?

Besides improving the health of your vegetable plants, eggshells are also believed to act as pest control. And one of the many pests that grace us with their presence are slugs.

The efficiency of eggshells as slug deterrent is a bit controversial. The idea behind this is that crushed eggshells would irritate the soft bodies of the snails and would keep them away.

Some say they have tested this theory, and slugs still continued making an appearance in their garden.

Because I haven’t tested this theory myself (since I really don’t like the sight of crushed eggshells in my vegetable garden), I cannot attest its efficiency.

Assuming that the crushed eggshells are larger, and you have a thicker layer of it on the soil, they could work as a slug repellent. So yes, in theory eggshells could create an inhospitable ground that slugs would avoid.

I also heard that the albumin content in eggs can keep deer away from your garden, but that means keeping the egg white in your eggshells too, because albumin is found in egg whites and not the shells.

Wrapping Up

If you bake often or simply consume lots of eggs, you can put eggshells to good use in your garden, as a fertilizer.

Use them steeped into water or crush them into a powder, and you have yourself an all-natural fertilizer that can strengthen the cellular structure of your plants and provide trace amounts of essential nutrients.

As with many other home-made fertilizers it’s important to understand that they may not be enough to supply all the nutrients needed for your plant.

As I recommended with using tea or coffee grounds as plant fertilizer, I will also recommend using eggshells only in addition to and not instead of a balanced fertilizer.

Articles   Updated: June 10, 2022
avatar Hi, I'm Amy, a devoted horticulturist and the creator of, where I use my expertise to help beginners foster their green thumbs. My blog is a vibrant community where I unravel the complexities of gardening and share my profound love for nature.
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