Worm castings are essentially worm poop, the natural fertilizer created when earthworms eat organic matter (like compost, leaves, and food scraps) and digest it. After passing through a worm’s gut, the material comes out as castings, which are packed with nutrients and beneficial microbes.
They’re considered one of the best organic soil amendments because:
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Nutrient-rich: They contain essential plant nutrients like nitrogen, phosphorus, potassium, calcium, and magnesium in forms that plants can easily absorb.
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Microbe-heavy: Full of beneficial microbes that improve soil health and help plants fight off diseases.
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Soil conditioner: Improve soil structure, water retention, and aeration.
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pH balanced: Naturally neutral, so they won’t burn plants like synthetic fertilizers sometimes can.
Gardeners often call worm castings “black gold” because of how effective they are at boosting plant growth.
