This article may contain affiliate links. We get paid a small commission from your purchases. More Affiliate Policy
Calcium is an important mineral for good, strong, healthy plants if you want an organic productive garden. After reading this blog, you will never throw away eggshells again. You will see how useful they are as a gardening hack.
Every day millions of eggs are eaten for breakfast, lunch, and dinner, but we are usually concerned about the internals of the eggs. However, eggshells are a useful resource in the garden, and most people waste them.
Table of Contents
What are eggshells made of?
Eggshells are made up mainly of calcium carbonate, around 50 ppm. They contain other minerals such as sulfur at 39ppm, potassium at 12ppm, magnesium, and 12ppm, and sodium at 21ppm along with these minerals, they also contain 5% organic matter.
The organic matter might shock you, especially since no one talks about it on other gardening sites. The inner white skin of the eggshell is organic. This organic matter contains nitrogen made up entirely of proteins. Plants can utilize this once it decomposes.
Now we know the makeup of eggshells, what benefits do they hold for the gardener? Eggshells are very handy in the garden. Firstly, for their calcium content, the egg’s outer shell is almost 94% calcium carbonate.
We know plants need NPK Nitrogen, Potassium, and phosphorous. Still, they also need calcium and other minerals to prevent diseases like blossom end rot in tomatoes, peppers, and eggplant. More on this a little later.
NEVER Throw eggshells away!
So I am here to tell you. DO NOT throw away any more eggshells at home. Instead, store them up in some container. Then when it comes time to use them, they can be washed and placed in the oven at 170f for half an hour. Or put it in the microwave for a few minutes. You would want to do this to your eggshells to eradicate any traces of bacteria like salmonella that can make you sick.
There are many ways to use eggshells in the garden. Some work, and others don’t or are just myths. I will cover these in a moment, but first, we must continue our eggshell prep.
Let’s take a look at eggshell uses.
When opening eggs to eat, just cut the top portion of the eggshell off, This will allow you to poke a small hole in the bottom and use it as a seed starter container. This is a great way to get children to grow in the garden.
Simply place the eggshells back into the cardboard egg box and fill each eggshell with compost and sow your seed. This will start the plants off to the seedling stage, where they can be planted in bigger containers or on the ground. Be sure to carefully break the eggshell before planting to allow the plant’s roots to escape.
If you grind the eggshell in pestle and mortar or use a blender or coffee grinder, you will get an eggshell powder. This can be used by adding it directly to the soil as an eggshell fertilizer. Or add it to the compost heap to add calcium directly, and this will slowly break down over time.
Eggshells And Worms
Add ground powdered eggshells to your worm farm, where worms will use it to help grind their food. Worms have a gizzard, like chickens, and require grit to digest the vegetable scraps you’re feeding them. You’re supercharging your worm castings by giving them eggshells in the wormery.
A few other uses for eggshells in the garden might be putting crushed eggshells down for birds, who will use it as grit. Add decorative value to the top of potted plants, and as this breaks down will fertilize your plants over time. The last method is to use the powder or eggshells in the planting hole of plants to ensure they do not suffer from a calcium deficiency. You can also mix it into a seed starting mix.
Eggshells And Slugs
One massive myth about eggshells which isn’t true, is that eggshells prevent slugs from eating your young tender plants like lettuce.
You break eggshells up and place a ring around each plant. The slugs won’t go near the plant because the rough surface cuts the slug’s mantel.
In my opinion, eggshells are not sharp to a slug at all. The mucous membrane the slug excretes while moving protects it from sharp edges, and much footage shows this to be the case.
Check out the video opposite if you want to beat slugs in the garden.
If you want some other ideas on how to beat slugs. I do have an upcoming video showing some more surefire slug deterrents that you may wish to keep an eye out for. To ensure you see that, consider subscribing to our FREE youtube channel. Also, check out my how-to eradicate slugs from your garden video.
Calcium Deficiency In Plants
Earlier we touched upon blossom end rot. This is caused by calcium deficiency. There are only ever two reasons for this. Either there is a lack of calcium in the soil. Adding the powdered eggshell would sort, or you have been watering irregularly.
This means the plant’s roots dry up and shrivel and can no longer utilize calcium. The plant’s take-up is poor until it recovers and produces new fibrous roots. Furthermore, blossom end rot is not a disease. There is nothing wrong with the plant that calcium or correct watering cannot sort out.
Everything we have spoken about takes time to break down so that the plant can utilize it. However, if you have plants lacking in calcium, there is a way in which to make it available right away. You need to make eggshell water. Otherwise known as calcium carbonate water. This provides calcium in a form that can be utilized immediately.
Make Eggshell Water
To add equal parts, add one tablespoon of ground eggshells to white vinegar. Leave this sit for about half an hour. The resulting mix will start to foam as the calcium in the eggshells neutralizes the acid in the vinegar. This will dissolve the calcium into a liquid form.
Once the reaction has stopped, you can add this mixture to a gallon of water. This is your concentrate, use 1 cup of this concentrate in a 5-liter watering can and water on your plants. You should see the plant perk up in a few hours as it takes up calcium.
You can also do this weekly with tomatoes as a preventative, and there will be no adverse effect if there is already surplus calcium, as the plants just won’t absorb it.
I hope this has been of interest to you. If you got value from this blog please share the love by sharing it. If you haven’t already, you can subscribe to the blog in the right-hand sidebar.