Why is vermicompost so great?

Why is compost that is produced with large numbers of worms assisting in the decomposition better than ordinary compost?  Vermicomposts are generally of finer structure, contain more nutrients and have higher microbial activity than other types of compost.

To appreciate why vermicompost is so great, you have to understand the inner workings of worms.  Many tiny organisms, bacteria, fungi, actinomycetes, enzymes and protozoa live in the worm's gastrointestinal systems aiding digestion. They are microscopic and thrive by the hundreds of thousands within a single worm. These organisms assist in preparing the nutrients to be absorbed and utilized by the worm.  The worm produces numerous enzymes which aid in its own survival, including an insecticide and an antibiotic.  These enzymes emulsify with mucus produced in the worm's gut and sheath the castings when expelled through the anus. Plants are able to absorb the insecticidal and antibiotic enzymes through their roots to further utilize them in the plants' ongoing battle to ward off insects and disease.

Worm castings test low on a normal soil report. The nitrogen level of typical vermicompost tests at less than 1 percent. Phosphorous tests around 1 percent or lower. Potassium tests slightly higher than 1 percent. These levels appear to be low but all of the nutrients in a casting are in a form that is readily available for use by the plants.  This low test goes against the advertising by chemical companies that higher and higher NPK ratings are needed to grow plants.  That is true within chemical fertilizers only!  Castings achieve the same or higher rates of growth without the high concentrations of NPK that is now known to be an environmental hazard to our waterways and soils.  Castings provide a successful and balanced growth to all plants without overuse of any one nutrient.

Vermicompost not only helps plants grow better, it also helps protect plants from diseases and pests.  All thanks to the lowly worm.  If you are starting your own seeds this spring, mixing vermicompost with your potting mix will give you great results.