Worm Castings - Frequently Asked Questions


What are worm castings?


Worm castings are the digested material (excrement) from worms.  They are rich in microbial life and include some very effective substances that help plants grow.


What is soil microbial life?


Soil microbial life includes bacteria, amoeba, protozoa, fungi, and nematodes.  These microbes digest organic material and each other creating nutrients that are made readily available to plant roots.  In a healthy soil, there are billions of these critters in just one teaspoon of soil.  In fact, in a teaspoon of healthy soil, there can be over 100,000 different species of bacteria alone!


This microbial life is an essential element in soil that is a functioning part of the earth’s ecosystem.  It breaks down dead organic matter into usable elements for the growth of plants.


Why are worm castings superior to other types of soil amendments or compost?


Worm castings have a wider diversity of microbial life than simple compost.  Moreover they naturally contain humates, auxins, kinetins, and cytokinins that act as plant-growth regulators that other types of soil amendments do not contain.  Science is just beginning to understand the importance of these chemicals.  They stimulate cell growth, the uptake of nutrients into roots, control the length of cells, and even act as an anti-aging compound so that plant cells do not decay as fast.


In addition, they contain the enzyme chitinase which dissolves chitin, a chemical that creates the hard shells of insects, thus acting as an insect repellent.


How are worm castings used?


Worm castings can either be mixed into the soil or applied on top of the soil as a top dressing and watered in.  Studies have shown that as little as 5% castings added to soil achieve dramatic beneficial results.  In addition, worm castings can be used to make worm tea.  Tea is used as a leaf spray to suppress disease or sprayed onto the soil to enhance microbe life.  Because of the chitinase in castings, someone has even applied for a patent for the use of worm tea as an insect repellent!


Are castings effective in disease and insect suppression?


Yes.  Plants given a wide variety of nutrients on which to feed rather than restricted chemical forms of NPK grow healthier, more bountiful and disease resistant.  Insects will attack weak or dying plants rather than healthy ones.


Are castings environmentally safe?


Yes.  Castings are child, pet, wildlife and earth friendly.  Casting are made in a natural process of worms eating organic material.  No man-made or petrochemicals are added.  In fact, our Barefoot Soil Earthworm Castings are made from worms fed washed dairy manure of cows that are hormone and antibiotic free.


In fact, worm teas are increasingly used in turf management rather than harsh fungicides.  For example Brandon Dunes Golf Course in Oregon is just one golf course that uses them exclusively with exceptional results.  Worm teas are also used in residential turf management and lawn care with results that sometimes far outperform chemicals.  Grass is healthier, thatch is reduced, and the soil becomes more water retentive not to mention the eliminated harmful effects of chemicals on surface and ground water and their toxic effects on all life.


Are castings high in NPK?


No, typically they are not.  However, growers find that less added nitrogen, for instance, is necessary to achieve equivalent growth results to soils that are not microbiologically enhanced.  One study said 1/60th the amount of nitrogen was required.  The biological life acts to transform nitrogen in the soil and convert nitrogen in the air to usable forms for plants.


What is the bottom line?


Volumes have been written on the beneficial results from the use of worm castings as a soil amendment and in worm teas, and they continue to be studied by research universities around the world.  Castings improve plant growth, improve soils’ water retention by increasing soil aggregates, are 100% organic, are non-toxic, can't burn, are odor-free and effect odor elimination, control or eliminate fungi, and create insect repellency.