Best for plants and the planet
Worm castings are worm feces. The castings are rich with live biological organisms. The organisms include fungi, actinomycetes, beneficial bacteria, pseudo monads, plant growth regulators, yeasts, molds, trace elements and the famous NPK ratings used by fertilizers, to reference the nitrogen, phosphorus and potassium quantities promoted by the fertilizer industry.
The truly revolutionary thing about worm castings as compared to traditional NPK fertilizers is these microorganisms ability to make more NPK available to plants, while containing far less of these elements. The NPK is far more bioavailable to plants, so we need not spread toxic levels to achieve our desired results.
The result is an odorless, child and pet-safe application that improves plant growth, soil structure and moisture retention — supported by lots of scientific research.
Worm compost can suppress disease, regulate nutrients Cornell University
Vermicompost Amended Soils Ward Off Crop Pests North Carolina State University