From the page: The shell that turns into gold in the garden
Idea 4
Accelerated composting
The eggshell is practically pure calcium carbonate, the same mineral as lime and chalk. In the composter, this calcium neutralizes the acidity of the decomposing material and feeds the microorganisms and worms, making the compost more balanced and rich — it's an old trick of homemade fertilizer makers.
What you need
- Eggshells (you can accumulate them in the freezer until you have plenty)
- Blender or mortar
- Composter, lidded bucket or worm farm
- Vegetable scraps, coffee grounds and dry leaves
How to make it
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1
Store the dry shells in a jar — you can accumulate them calmly, because dry they don't create mold or odor.
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2
Grind until it becomes powder or coarse granules: once ground, the shells decompose in weeks instead of months, because it exposes much more surface to the action of microorganisms.
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3
Spread a thin layer of the powder in the composter whenever you add food scraps, alternating with dry material like leaves or cardboard.
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4
Turn the pile once a week to let air in — aerobic decomposition (with oxygen) is faster and odor-free.
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5
In a few weeks the powder will have blended into the compost, ready to become fertilizer for pots and the garden.
Finishing touches
A pinch of this shell powder can also be applied directly to pot soil to correct very acidic earth, like that of ferns that turn yellow. If using in a worm composter, small doses are ideal — worms appreciate it, but don't overdo it.
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