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7 Plants That Like Eggshells (And How To Process Them)

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Eggshells are made of biodegradable materials that are surprisingly nutritious for your plants. So, you’ve probably been throwing away free fertilizer without even knowing it. But how do you process eggshells, and what plants can benefit from eggshell powder?

There are several plants that can benefit from homemade organic eggshell powders, including:

  1. Tomatoes
  2. Cabbage
  3. Cauliflower
  4. Broccoli
  5. Pepper
  6. Eggplant
  7. Cucumber

The rest of this article will cover the best plants to use eggshells powder on, along with everything else you need to know about using eggshells for plants.

How Do You Prepare Eggshells for the Garden?

You prepare eggshells for the garden by crushing and boiling them. Boiling the eggshells for 5–10 minutes disinfects and breaks down the eggshells. You can also wash, dry, and grind eggshells into a fine powder using a food processor.

After washing your eggshells, you can dry them quickly (helping reduce bacteria and mold growth) by baking them in an oven at 350℉ (176.7℃) for about five minutes. After baking, the eggshells will be brittle, making them easier to grind into a fine powder.

When you’ve created your eggshell powder, you’ll have two options for how to use them: Sprinkling them onto the top of your garden soil or spraying them onto the soil as a liquid fertilizer.

To make a liquid eggshell fertilizer, add one to teaspoons of powdered eggshell to one liter (33.8oz) of water. Shake vigorously for five to ten minutes, then spray the solution onto garden soil.

Hand feeding crushed eggs shells onto a plant
You need to process eggshells more than this.

What’s the Best Way to Fertilize Plants With Eggshells?

The best way to fertilize plants with eggshells depends on the number of nutrients your plants need. For example, a liquid eggshell fertilizer might be best for plants that require immediate nutrients. But powdered eggshell sprinkling on the soil provides a more gradual nutrient dispersal.

Grinding the eggshell increases plants’ surface area to uptake the nutrients, as you can shake the powder across the top of the soil instead of spraying them directly into the soil. You can also mix the eggshell powder into the soil for immediate nutrient incorporation. 

Homemade liquid eggshell fertilizer acts far more quickly, as water will seep through the soil and reach a plant’s roots in minutes.

Consequently, a liquid fertilizer might be best for plants with high nutrient needs (like tomatoes). In contrast, a powdered mixed-in eggshell fertilizer could be the better choice for plants with moderate nutrient needs (like cucumbers and peppers).

The Effect of Eggshells on Plant Growth

Eggshells are a rich source of calcium nutrients, a micronutrient many crops need to blossom. Most notably, vegetables require calcium to thrive. Eggshells contain basic calcium carbonate. This aspect is helpful for soil pH regulation, as extremely low or high pH affects nutrient uptake in plants.

Therefore, eggshell powder as a bio-fertilizer helps lower soil acidity, creating a conducive soil environment for optimal nutrient uptake. In addition, bio-fertilizers comprising powdered eggshells help reduce soil salinity and raise soil conductivity

In these aspects, both soil health indicators are enhanced by using egg-shell-based organic fertilizers, improving the robustness of the soil. Soil conductivity measures the levels of the amounts of nutrients in the soil.

Low soil conductivity (SC) is an indication of insufficient nutrients absorbable by the plant in the soil medium. This is because the soil’s high electric conductivity indicates the presence of more anions (negatively charged ions), organic content, and cations in the soil. 

Cations take care of essential plant micronutrients like calcium, iron, magnesium, and manganese, all accessible to plants for uptake.

Eggshells contain essential micronutrients for plants’ fruiting and growth, including magnesium, calcium, iron, and manganese. As a consequence of using this bio-fertilizer, plants can take up sufficient nutrients more effectively at every phase of growth and development. 

This quality of eggshells fertilizers ensures healthy plants and optimum farm production.

What Plants Are Eggshells Good For?

Eggshells are good for vegetable plants like cabbage, cauliflower, and broccoli, as well as botanical fruits like tomatoes, peppers, eggplants, and cucumbers. Eggshells are rich in calcium and other minerals that enable the plants to grow and produce better yields.

Aside from calcium, eggshells contain trace amounts of useful minerals like manganese, iron, magnesium, phosphorus, and calcium carbonate.

Discarded eggs shells powder can act as a good alternative for plant fertilizers due to its rich calcium fortification. In addition, eggshells contain calcium carbonate, which is highly alkaline. They also regulate soil pH.

Therefore, eggshells offer an organic plant nutrition solution that is eco-friendly at virtually no additional costs.

Additional beneficial qualities of eggshells as fertilizers include:

  • Lower soil pH for optimal nutrient absorption by plants.
  • Help lower soil salinity and increase soil conductivity, availing more nutrients for plant uptake.
  • Improve the aeration of the soil.
  • Crushed eggshells have rough edges, a deterrent to pests like slugs, cutworms, and snails that attacks crops.
  • Can be used to mulch plants when spread at the plant base, aiding water retention.
  • By ensuring low salinity in the soil, the crushed eggshells help minimize water uptake stress caused by hypertonic soil.
  • Helps curb the problems associated with poor drainage of soil that could be detrimental to certain crop varieties.
  • Eggshells are organic and biodegradable, making them suitable soil rectifiers and amenders in soil engineering.
  • Serves as a good alternative to chemical pesticides and fertilizers.

These are just a few notable qualities of eggshells that are beneficial to plants and plant growth. Be sure to check out the table below for a quick breakdown of how eggshells affect specific plants:

Type of PlantRequired NutrientsRecommended Frequency of Fertilization
TomatoCalcium, phosphorus, magnesium, sulfurOnce per month; Most crucial during early growth stages
CabbageCalcium, zinc, magnesium, sulfurEvery two to four weeks
CauliflowerNitrogen, potassium, manganese, magnesiumEvery four weeks
BroccoliCalcium, magnesium, boronAccording to growth, before germination, when plants reach 6in (15.2cm) in height, when plants are 14in (35.6cm) in height, when buds form
PeppersCalcium, iron, phosphorus, magnesium, nitrogenEvery two to four weeks
EggplantCalcium, potassium, phosphorusEvery week or one every two weeks
CucumberPhosphorus, potassium, calcium, ironEvery two weeks

Eggshells for Tomato Plants

Tomatoes in containers on a garden terrace

Eggshells are great for tomato plants as they contain core nutrients like calcium and magnesium. Tomatoes have varying needs and nutrient requirements for every stage during their growth cycle, making eggshells a beneficial fertilizer to use.

However, nutrition needs vary for other co-minerals vital for healthy tomato growth.

For instance, potassium and nitrogen uptake are slow until the flowering stage. Typically, the potassium requirements in the tomato growth cycle spike in the fruit development stage. Nitrogen demands of the plant will rise after developing the initial fruit.

Vital nutrients present in eggshells suitable for tomatoes include:

Calcium

When tomatoes commence fruiting, high growth rates of the plants may cause periods of calcium deficiencies. Usually, this is characterized by necrosis of the fruit’s apical ends. 

This aspect is a phenomenon where the apical section of the fruits starts to die in response to a particular deficiency that causes plant stress. A sufficient supply of calcium ions by eggshell bio-fertilizers can help curb necrosis in tomato plants.

Calcium-rich eggshells are essential to the tomato as it’s a predominant constituent of the plant cell walls. Adequate calcium supplies to the tomato plants help reduce plant vulnerability to infections and diseases. 

In addition, calcium helps lower soil salinity (which can cause dwarfism in plants) and raises soil conductivity, optimizing uptake of vital nutrient supplies from eggshells from the soil. 

Iron, Magnesium, and Manganese

Insufficient supplies of these three crucial minerals lead to tomato plant chlorosis, meaning a lack of chlorophyll. The plant leaves turn pale brown and start to wither. 

The magnesium component is vital for the formation of chlorophyll, for light trapping is essential to photosynthesis in tomato crops. Iron micronutrients traces in eggshells powder are vital for synthesizing chlorophyll in tomato plant leaves.

Essentially, sufficient manganese, magnesium, and iron uptake by tomato plants help support the phototropism for a healthy plant.

Boron

The trace nutrients boron in eggshells is vital for forming the cell wall in plant cells. In addition, this trace nutrient enables elongation of the pollen tube, facilitating seed dispersal for pollination. Further, it takes part in the metabolism of plants while aiding the translocation of sugars.

However, this nutrient needs to be regulated in its supply. This is because excess boron can be toxic as it becomes challenging to translocate in the phloem vessels of the plant. 

Boron deficiency symptoms are characterized by leaves turning green to yellow to orange taint. In addition, the stems will appear swollen and brittle.

Zinc

Finally, zinc helps develop plant hormones, auxins that help promote the growth of both roots and shoots in the tomato plant. A lack of zinc in tomato plants manifests through interveinal necrosis. This condition makes the leaf veins’ upper section turn brown and wither off.

These nutrients constitute the dominant nutrients-need for tomatoes during their growth cycles for a productive harvest.

The eggshells organic fertilizers offer an eco-friendly remedy to ensure proper tomato plant health and secure a bountiful tomato harvest.

Are Eggshells Good for Cucumber Plants?

Eggshells are good for cucumber plants. Cucumbers require a soil pH of between 6.0 to 6.8 and an adequate supply of calcium in their growth cycle, both of which can be achieved using eggshells as fertilizer.

A lack of this nutrient could lead to plant stress and starting with blossom end rot (BER) symptoms. This term refers to the blackening of the lower bottom end of the cucumbers caused by rotting due to calcium deficiency.

However, egg shell-based fertilizers have a high percentage of calcium ions that protect the cucumbers and eggplants against BER syndrome. In addition, when incorporated with soil, crushed eggshells lead to soil aeration and help improve water drainage. 

Cucumbers thrive in a non-soggy, well-drained environment. Further, eggshell mulch can help ensure that the cucumbers are well watered.

Further, calcium-rich eggshell fertilizers help balance the soil pH to the required average of 6 to 6.8 for optimal cucumber growth.

Are Eggshells Bad for Any Plants?

Eggshells, overall, are suitable for plant fertilizer alternatives as they contain vital nutrients essential for most plants’ health. However, users of these bio-fertilizers should understand the optimal nutrient requirements for the plants they grow. 

For starters, excess calcium could significantly raise the soil pH to levels unsuitable for plant growth. Further, the misapplication of eggshells through improper drying could be detrimental to plants. 

Using raw eggshells can attract notorious pests to your garden or farm without cleaning with distilled water. For instance, rodents love the smell of freshly crushed uncleansed eggshells. 

If your old eggshells are adequately washed and dried, then the eggshells may entice pests to your garden instead of deterring them.

When used properly, eggshells are not bad for most plants. After all, eggshells are ideal calcium-rich biofertilizers that help promote plant growth and plant welfare.

Do Houseplants Like Eggshells?

Most houseplants can benefit from an eggshell-based fertilizer, but some aren’t so appreciative. Generally, the best houseplants to pair with eggshell composts are those that require above-average amounts of calcium, boron, iron, magnesium, and zinc.

Houseplants that thrive after receiving a dose of eggshells include aloe vera, potted ficus, and rubber trees. A monthly dosage of powdered eggshells can benefit any indoor plant, and this organic compost is far safer than commercial fertilizers.

Before tossing your old eggshells into your indoor potted plants, be sure that they’re not moldy or smelly. It’s also an excellent idea to pulverize your old eggshells with a food processor to turn them into a fine powder.

Powdered eggshells can seep into your plant’s soil far more easily than whole shells. They’re also far less likely to attract pests like roaches and rats.

A Composter With Eggshells on Top
Adding eggshells to compost should be common practice.

Key Arising Issues in the Use of Eggshells Fertilizers

Despite the obvious upsides of eggshells as a viable bio-fertilizer, more research is needed.

Finely powdered eggshell fertilizers are an environmentally-friendly approach to plant nutrition while minding soil well-being and deserve better research for their far-reaching merits. For instance, it contributes and addresses issues soil health, biosecurity, and food security efforts in the face of climate change.

For more, don’t miss Can You Compost Brown Paper Bags?

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