Plants need water, light, air and food. In gardens and on balconies, the supply of nutrients is all too often provided by ready-to-use fertilizers sold in plant and garden stores, which usually contain chemical additives, are packaged in plastic and also cost money.

Yet every household produces valuable organic waste on a daily basis, which is disposed of either in the organic garbage can, the compost bin or the bokashi bucket. It’s easy to make a DIY fertilizer from many organic leftovers that can replace finished products – from eggshells, for example.

Why are eggshells a good fertilizer?

Lime (calcium carbonate or CaCo3) is an elementary component for healthy plants, as it enables the absorption of all other minerals. Lime loosens the soil and creates optimum conditions for roots to absorb nutrients. With 90% limestone, eggshells are an excellent source of lime.

Lime isn’t the only advantage: the 27 other micronutrients contained in eggshells are also very interesting. These include fluorine, copper, iron, manganese, molybdenum, phosphorus, sulfur, zinc and silicon.

Making your own eggshell fertilizer :

To make liquid fertilizer from eggshells, you need just two ingredients:

  • 1 to 2 eggshells
  • 1 liter of water

Here’s how you do it:

Crush or grind the eggshells into as fine a powder as possible – using a mortar, blender, coffee grinder or spice grinder, for example. Two planks of wood between which the eggshells are crushed also work well.
Place the ground eggshells in a container and pour in a liter of water. Leave to stand for 12 hours to allow the minerals in the water to dissolve.
Pour the water through a fine sieve or filter bag into a watering can.

Your liquid limestone fertilizer made from kitchen waste is ready!

Tip: you can spread the undissolved peelings on the soil around your plants, or compost them.

Tips for correct fertilization:

  • As is often the case, too much fertilizer is not beneficial. It is therefore advisable to take into account the needs of your plants and the lime content of the water.
  • Some plants like limestone, others are sensitive to it. This preference is expressed by indications on the required acidity range of the potting soil. It’s also useful to know the lime content of the tap water or irrigation water you use. If you live in a region where the water is very hard.
  • A simple pH test can give you extra security as to the nature of the potting soil and the water used for watering. The easiest way to do this is to use special pH test strips, which you can find in pharmacies, plant stores or online.
    If you adjust your fertilizer dosage accordingly, your plants will thank you with healthy, abundant growth.
    To find out how to turn other organic wastes into natural fertilizers for your plants, see the article Waste as fertilizer. Plant purines are also a natural fertilizer rich in nutrients – nettle purine, for example.

Have you ever experimented with homemade fertilizers? We’d be delighted if you’d share them with us in a comment!