Gaia Green Worm Castings are the unprocessed, natural manure of African Night Crawler earthworms. African Night Crawlers' castings are the highest quality available. They are high in beneficial bacteria, organic matter, humus, nitrate nitrogen, calcium, magnesium, phosphorus and potassium in an easily absorbable form. Gaia Green Worm Castings contain all the necessary nutrients for vigorous plant growth. ?However, Gaia Green Worm Castings are most commonly used as a bioinoculant to reintroduce the full range of micro-organisms into the soil or growing media. This odourless material provides good aeration, moisture-retaining capabilities, and will not leach from the soil. This excellent all-purpose fertilizer can be mixed with any of our Gaia Green blends for outstanding results.