Eggshells can be used in a variety of ways to enrich your garden. Eggshells provide a valuable source of calcium for growing plants and also deter certain pests without the need for chemicals. Eggshells consist of 93% calcium carbonate and other trace elements that make them a practical fertilizer. The composition of an eggshell is very similar to that of our bones and teeth. A medium sized eggshell makes about one teaspoon of powder, which yields about 750 - 800 mgs of calcium. Eggshell calcium is probably the best natural source of calcium, and it is easy for the human body to digest and absorb too. In fact many people eat powdered egg shells as a dietary supplement.
Likewise your plants can also benefit from this source of calcium. In the garden, for fertilization purposes make sure you crush the eggshells before you add them to your garden. Crushing the eggshells helps them to break down so that they may readily supply calcium to your plants. Without adequate amounts of calcium, plants experience a variety of problems. If calcium is deficient the cell walls of a plant become weak and unstable. The stronger the cell wall, the stronger the plant, and the quicker its recovery from the enormous pressures that it is faced with in the garden. This applies for both leaves and roots. The stronger the root cells are, the more aggressively the roots will be moving through the soil. Sufficient levels of calcium also assist in the efficient use of sunlight, carbon dioxide, water, nitrogen and minerals. Calcium also plays a major role in the construction of numerous hormones, and enzyme systems that can help protect the plant from insect and disease attack.
To prepare, your eggshells should be washed first or they could attract pests into your garden. Put the shells in a plastic bag and then crush them by hand, if you are really dedicated you may then powder them in the blender if desired. The powdered or crushed eggshells are best placed around fruit trees, tomatoes, roses and in potted plants, though it will be of benefit anywhere in the garden! The powder is very useful for tomatoes because the extra calcium will help prevent blossom end rot. This is a condition which causes tomatoes and other vegetables to develop black patches on one end. Blossom end rot is caused by insufficient calcium or poor absorption, so a ready supply at root level is a good preventive measure.
Sprinklings of crushed eggshells can be added and tilled directly into the garden soil. They can also be added to the soil mixture of seedlings or to the bottom of potted plants. The water used to cook hard boiled eggs is also a valuable source of calcium. Allow the cooking water to cool to room temperature and then simply pour it around the base of vegetable or house plants to provide added nutrients. Alternatively you can soak the crushed eggshells in water for a few days to make a ‘calcium tea’ to feed your plants with.
Crushed eggshells can also naturally assist in deterring some pests from a vegetable garden. There is nothing worse than growing a vegetable or fruit from seed only to come out one morning and see it has been eaten and destroyed by slugs or snails. Snails require a smooth surface to move. If they come across a barrier of sharp grit they will not be able to pass. The sharp edges of the shells can be deadly to any slithering creatures, such as slugs and cutworms. Spread crushed eggshells around the base of seedlings. When the pests such as snails or slugs make their way toward the plants, they will be deterred by the rough edges of the crushed shells. For organic growers this is also the best way to protect your plants, it is the cheapest easiest and most natural solution. Not only are you protecting your plants from being eaten and destroyed you are also giving them extra food as well.
Eggshells can also be used as planters for small seedlings and be put directly in the ground for planting. Make a small drainage hole in the bottom of an empty eggshell, with a pin. Add soil and put it in an open egg box. Sow the seeds and care for them as you would any other seedlings. The shell will provide a natural slow release fertiliser for your seed as it germinates. When the seedlings are ready to transplant into the garden, squeeze the shell gently to crack it and then place it in the ground. The roots will push through the cracks in the shell which will decompose naturally.
Another commonly discarded kitchen waste item is coffee grounds (tea leaves as well for that matter), which can be particularly useful in the garden. Used coffee grounds contain about two percent nitrogen, and many trace minerals. They are particularly useful on those plants for which you would apply an ‘acid food’ such as evergreens, azaleas, roses, camellias, avocados, and certain fruit trees. I store old coffee grounds in a tin and then scatter them lightly mainly around the roses. Don’t scatter them thickly when they are wet, because the coffee grounds have a tendency to get moldy.
