How to Use Eggshell As Fertilizer (Step-by-Step Instructions)


Not all gardeners realize that a simple eggshell can act as a wonderful fertilizer. You can use eggshells to keep the soil balance in an organic way. It is important to properly prepare the eggshell so that it benefits. 

The shell contains calcium carbonate, potassium, magnesium, phosphorus, which have a beneficial effect on houseplants.  In this article, I’ll share how you can use eggshells as fertilizer, deoxidant or pest control products.

The Chemical Composition of Eggshell

The eggshell is not only the protection of the embryo. It contains a complex of substances and valuable elements.

The main component of its composition is calcium carbonate. The interesting fact is  95% of the structure of the eggshell is composed of this component. 

In addition to calcium carbonate, eggshell contains other elements necessary for the development of houseplants:

Element100 g chopped shell (fresh)In 100 g (after calcination)
Calcium carbonate35 g30 g
IronUp to 4.2 gUp to 2.5 g
ZincUp to 650 mgUp to 3.3 g
Magnesium410 mg1050 mg
SulfurUp to 1300Up to 1 g
PhosphorusUp to 170 mgUp to 12 g
ManganeseUp to 120 mg420 mg
SodiumUp to 130 mg650 mg
Potassium85 mg20 mg

Source: National Center for Biotechnology Information

Besides the above elements Molybdenum, iodine, cobalt, chromium, and fluorine are also present.  But after heating these elements decay.

The film covering the eggshell from the inside is 3-4% of the organic matter.  The membrane is rich mainly in keratin and mucin. 

The percentage of elements is small.  But when you use them regularly, it does not go unnoticed, giving the soil additional food.

The Use of Eggshells for Houseplants

Mixing crushed eggshell with  houseplant soil

You can use eggshells as fertilizer in case of high soil acidity, as well as in areas with clay soil. Here’s why you should use eggshell as fertilizer:

  • A decrease in acidity. The optimal pH level of the soil is 5.5-7. I should remind you that lower the pH value more acidic the soil is. The acidity helps accumulate toxins and substances that prevent nutrients from entering plants. Also, it reduces the processing organics into humus. Due to the high content of calcium carbonate, eggshells raise the pH to acceptable values for houseplants. 
  • Improvement of soil looseness. On heavy soils, plant roots suffer from a lack of oxygen and water stagnation. And lack of water causes the ground to crack. And this leads to damage to the root system. Now, eggshells come with the rescue. It helps loosen the soil, preventing the formation of hard crust on the surface. As a result, eggshell fertilizer improves the aeration of roots. Soil can absorb the water evenly and drain out excess water without stagnation. 
  • Soil mineralization. You can use eggshells with other fertilizers as an organic supplement for minerals. It will also help neutralize the acid properties of mineral fertilizers.
  • Protects against pests. Eggshell can protect your houseplant from pests. So You can use it as one of the pest control methods.

You can use eggshells to protect plants from pests, in particular from snails. In this case, crush the eggshells with your hand, but not to the state of the powder. Then scatter around the stem. The sharp edges of the eggshell will become a hindrance for snails and other pests that cannot easily get to your plants and damage them.

  • Germination improvement. Eggshell can increase the seed germination percentage and strength of young shoots. Sow the seed with crushed eggshell you will get the result.
  • Root supplements. In order to quickly deliver nutrients to the plants, you should water them with a special solution using crushed shells. Take the dry hard shells of five eggs and crush them into powder. Pour the mixture of boiling water, cover and keep in a dark place for one week. Stir the mixture daily. Dilute the resulting mixture with the water to a 1:3 ratio. Then apply it to your plants. This method is used to increase the yield of beets, peppers, tomatoes, etc.

Eggshells are enriched with minerals, loosens the soil and prevents the development of diseases such as apical rot and blackleg.

In order to reveal the positive properties of all components, it is necessary to familiarize yourself with the proper use of eggshells for indoor plants.

Collecting Eggshells

You have to collect and store the shells correctly before using it as fertilizer. You may face a common problem during the collection of eggshells.

The smell of the rotten eggs after storing it. No worries, there are 2 methods, you can use to store this organic fertilizer without smell.

  • The first option is to rinse with water before storing it. So you can get rid of the remnants of organic matter and films. 
  • The second method is baking in the oven at high temperatures. 
Collecting eggshell to make fertilizer.

After washing properly you can dry them next to the heater or in the sun. This way you can get rid of the smell.

But the downside is that the films contain valuable substances that will simply be removed when you wash them.

You cannot use plastic bags to store raw materials, as the product will accumulate moisture and deteriorate.

Calcination is a more troublesome method. As you will still have to collect a certain number of shells. However, it will be easier to crush the eggshells and break it into powder.

Advantages and disadvantages

Before applying this fertilizer, it is necessary to understand how the fertilizer acts on plants. Also what negative reactions it can cause. The advantages of eggshell fertilizer include:

  • In terms of the content of useful microelements, the shell is superior to many industrial fertilizers. Also, in contrast to the readymade product, it is several times cheaper;
  • Fertilizing with this  will benefit almost all plants
  • The use of the eggshell accelerates the growth of plantings and increases yield;
  • Eggshells scare away many garden pests;
  • The product does not contain chemicals, therefore, it is not harmful to humans and the environment.

In terms of disadvantages, eggshell can cause the following undesirable effects:

  • Some indoor plant species do not receive such fertilizer supply. Therefore, it is impossible to predict their reaction;
  • An overdose of the beneficial substances contained in the shell can cause harm to plants.

If you use this bait properly and only for suitable plants, it is guaranteed not to cause harm.

Source: International Journal of Scientific & Engineering Research

Preparation of Egg-shell Extracts and Fertilizer for  Indoor Plants 

Using eggshell extract as fertilizer for indoor plants.

One of the most popular ways of egg-shell application is the preparation of liquid fertilizer extract. You can use this extract for indoor plants and flowers.  But it may also be suitable for seedlings grown on a window sill, or for crops already planted in the garden.

Step 1. Collect your eggshells. Preferably, it should be as whole as possible. The shells left after using raw eggs are preferable to the one left after cooking. Because, it contains more useful macro-and micronutrients that are essential for your plants.

Step 2. Rinse the inside of the eggshell with warm water. This is necessary to remove protein residues. Otherwise, this will begin to rot and give an unpleasant odor when applied as fertilizer. 

Unfortunately, this is unavoidable when preparing the eggshell solution. But you should minimize this problem by washing the raw material.

Tip!

In some cases, after (or before) washing the eggshells you can dry them up in an oven.

Step 3. Fill a jar of 1-liter with hand-crushed eggshells. If you wish, turn the eggshell into a very fine powder using a coffee grinder or meat grinder.

Step 4. Fill the jar with warm water, screw the lid tightly and let the liquids in. Approximately 5 days for a 1-liter container. Shake the can every day. An indirect sign of solution readiness is an unpleasant smell and turbidity of water.

Step 5. Pour the solution from the can into the water bottle at a ratio of 1:3 and then stir together. The resulting solution will contain nutrients. Water your indoor plants or seedlings with it. And this macro and microelements will reach them in the easiest way.

Step 6. Repeat the procedure, pour the water back into the shell jar and let it settle. You can do this 3-4 times with the same source material.

Some gardeners and experienced owners of indoor plants prefer to use snow instead of tap water. It is cleaner and contains no excess chlorine or iron.

Source: University of Illinois Extension

Preparation of egg-shell powder – step-by-step instruction 

Preparation of egg-shell powder with mortar.

You have learned about liquid fertilizer made from the eggshells. Here’s another common way to use egg-shell powder as fertilizer is to grind the source material to a state of loose powder. You can use this power for your indoor plant pots. 

Let’s start the step by step process.

Step 1: Start by collecting the source material, the eggshells. You should accumulate it in advance, starting from the autumn-winter period. 

The best fertilizer is the eggshell from raw eggs. The leftovers of boiled eggs show lower performance. This is because in the process of cooking some of the useful elements of them are gone.

Step 2. Put the eggshells in some kind of storage container. This can be a cardboard box, a glass jar (with the lid loosely closed) or a fabric bag.

You should avoid using plastic bags or plastic containers for this purpose.  The eggshells need a little bit aeration. 

Important!

Please note that the eggshells start to smell bad when stored. The reason for this is the protein residues on the inside surface, which begin to rot and decompose over time. Washing the eggshells in warm water or burning them in the oven will help to solve this problem. But you will lose some of the useful minerals contained in the eggshells.

Step 3: In spring, before or in the middle of the summer season, start preparing egg-shell powder. There are many ways to do it. Here are some easy ways to do it.

  • Cut the eggshell into medium pieces and then grind it into a mortar. This method is labor-intensive but requires nothing more than mortars and pestles. 
  • Pack the shell in a dense bag of fabric and then either roll out the rock many times or use a hammer to crush. In this case, you can crush them faster, but some small particles may remain intact. 
  • Crush the shell by hand into medium pieces and then grind it to a powder state in a grinder. One of the most effective ways to do this is to get loose fertilizer. This fertilizer is very easy to use.
  • Some gardeners grind the eggshells in a blender (pre-diluted with water) or a meat grinder. In terms of efficiency, these methods are less efficient than coffee grinders, but they are quite applicable.

Important! 

When working with eggshells, be careful. if you are not careful, you may injure yourself on the sharp edges.

Step 4. Pour the resulting powder into a cloth bag or jar and store the container in a dark and warm place until immediate use.

Here is a helpful video to understand how to use eggshell for plants:

Application of Egg-shell Powder Fertilizer to Indoor plant

Now that you have prepared the eggshell fertilizer powder, it’s time to know the application procedure. You should not apply the egg fertilizer all at one. Do it gradually. Let’s know when and how to apply.

The first time is when planting seeds or seedlings along with other organic and mineral fertilizers. In this case, apply from 30 to 50% of the total number of shells you used. This process is called primary dressing.

Split the remaining amount of powder into equal shares and  apply with other fertilisers. As there are not many eggshells to use, do not just spread them over the container. Make holes around the plant and put  eggshell fertilizer directly into it.

Given that eggshells do not happen much, it is rational to not just scatter them over the garden, and make directly into the holes around the stems of plants.

So if you have a little egg-shell fertilizer, then use it only on the most important plant pots, apply it rationally.

Best Plants for Eggshell Fertilizer Application

It is important to know which plants are suitable for eggshell fertilizer application.

Below is the list of plants on which this fertilizer will have the best effect. 

  • Orchids
  • Rose
  • Tomatoes ; 
  • Lettuce and other herbs; 
  • Rutabaga; 
  • Eggplant ; 
  • Pumpkin and other gourds; 
PlantRecommendationsDosage
CabbageWhen planting in the hole and when making chemical fertilizersAbout 5 tsp.
GourdsDuring the planting of the seeds and when necessary to supply nutrientsAccording to the needs
Solanaceous crops (potatoes, bell peppers, tomatoes, eggplant)Mix the eggshell powder with the soil when planting, seedlings watered with infusion of eggshell, diluted with water 1:3.Dry powder not more than 50 g per Bush
The herbs and onions, cucumbers, zucchini, beansUsed during the growing season, the powder used in the fall and spring when diggingPour eggshell extraction to seedlings and adult plants every 14 days
StrawberryMixed with ash of 1:1 ratio and apply to soilThe handful under a Bush
Shrubs (raspberries, gooseberries, currants)In the spring after defrosting of the soil.  In  fall sprinkle the crushed  power to loosen the soilFill no more than 0.5 g into a 1 m diameter of circle around the plant, then loosen the soil.
Fruit trees, Apple, pearDepending on the age of the plant with flour sprinkled around the trunk at a distance of 1-1.5 m, then loosen the soilFor fruit trees the rule is  0.7g per 1 m²
Perennials: roses, delphinium, clematis, lavender, peony, barberry, tulipsApplied to the soil at planting powder can with ash 1:1. Watered with a solution of 1-3 times in 20 days
Annual flowers: chrysanthemums, stocks, asters, bellsWater with Eggshell extract twice a monthAccording to the need
Indoor PlantsMix the eggshell fertilizer with soil. Water with the solution after transplanting I already described how you can make the eggshell solution

What kind of plants are not Suitable for Eggshell Fertilizer

Before using an eggshell as fertilizer, you have to know which plants will not be suitable. Excess calcium can cause a lot of diseases in houseplants.

Especially in gloxinia, violets, azaleas, hydrangeas, gardenia, camellia, geraniums. As such plants like acidic soil and eggshell reduce fertilizer.

You should also avoid using eggshell fertilizer in plants such as cucumbers, strawberries, cabbage, beans, and spinach.

Important!

If you combine eggshells with other organic or mineral fertilizers, then adjust their dosages for each plant. Remember that excessive amounts of certain chemicals are just as harmful to crops as the lack of these micro and macro elements.

Eggshells for Seedlings

And finally, you can find a good use for the eggshells. In them it is possible to sow seeds of small plantations. So, it is  guaranteed such methods are not only friendly containers, but also the natural top dressing of seedlings.

Here is the step by step process of using eggshell as a seedling container. 

Step 1. Prepare the eggshell. It should be from sufficiently large eggs (for purchased eggs, this is the “selected variety” group, also known as C0). There should not be any cracks or damage in the eggshells. So when breaking it for yolk be careful not to crack it more than one place. 

Step 2. Wash the inside of the shell with warm water. In the lower part, carefully make a hole with a push pin or needle. It is necessary for drainage. If there is no hole in case of excessive watering, the soil of the seedling will be excessively wet.  This will affect the seedling health. Excessive watering makes favorable conditions for diseases.

Step 3. Fill the eggshell in half with the soil. You are going to use it for  germinating seedlings. So, it is better to use soil with nutrients. Ready Mix soil is available in the market. Check the latest price on amazon here. You can use them without doubt.

Step 4. Place the seeds in the eggshell pots that we prepared with soil. Sprinkle with earth on top. Pour a small amount of water if necessary.

Step 5. Place the eggshell pots on the egg tray or box in which you bought them from the market. Then put them all together on a window sill, in the sunlight. Wait until the seedlings are ready to be planted in the soil. Do not forget to monitor the plants and water them regularly.

Step 6. When the seedling reaches the desired size, plant it in the larger container right in the egg shell. Squeeze the last one slightly to break it, but do not damage the seedling. In this way, the eggshell will decompose in the ground over time. And the seedlings in the container will have useful nutrients for growth.

Conclusion

If you have a garden or indoor plants, it is very useful to use eggshell as fertilizer. 

It is an excellent fertilizer, containing calcium and many micro and macro elements (fluorine, iron, silicon, zinc, copper, manganese). You only need to clearly understand where and in what form to apply it.

Arifur Rahman

I'm the owner of gardenforindoor.com. After completing my bachelor of science in agriculture, I'm serving as a civil service officer at the Department of Agricultural Extension, Bangladesh. I started Garden For Indoor to make your indoor gardening journey easy and enjoyable.

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