What are Worm Castings?

Worm castings are the byproduct of worms eating organic matter that would otherwise be thrown in the landfill.  This includes kitchen scraps, wood chips, lawn clippings, cardboard, etc.  As the organic material passes through the worms' gut, the end result is an extremely rich and nutrient-dense organic fertilizer.  Worm Castings (sometimes known as "vermicast" or "vermicompost") are dark black in color and have a similar texture and size to coffee grounds.  They are packed with millions of beneficial microbes, enzymes, bacteria, fungi, and minerals.  When you put worm castings into your soil and water it in, your are adding this entire ecosystem of beneficial microbiology into your soil - essentially adding life back to your soil.  This microbiology will continue to populate your garden and turn your other organic material (i.e. traditional compost, dead leaves, wood chips, etc.) into water soluble fertilizer - which is what makes worm castings so powerful and long lasting.  A small amount of castings goes a very long way.

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Worm castings are the last layer of decomposition - which is several steps further than traditional compost.  Nutrients in traditional compost can still require several years to unlock, which can be great for established gardeners who want extremely slow release fertilizer.  But worm castings are already water soluble and slow release.  A lot of gardeners will mix worm castings with traditional compost to get the more immediate results of the worm castings, and allow the microbes from the castings enhance and speed up the decomposition of the traditional compost.