Vermicomposting Glossary


Rocky the Wormacid Normal product of decomposition. Redworms do best in a slightly acid (pH just less than 7) environment. Below pH5 can be toxic. Addition of pulverized egg shells and/or lime helps to neutralize acids in worm bins.

actinomycete A group of unicellular microorganisms with characteristics of both bacteria and molds. They decompose dead plants and are responsible for the rich, earthy smell of compost and vermicompost.

aeration Exposure of a medium to air to allow exchange of gases.

aggregation Clustering, as of soil particles, to form granules that aid in aeration and water penetration.

albumin A protein in cocoons that serves as a food source for embryonic worms.

alkaline Containing bases (hydroxides, carbonates) which neutralize acids to form salts See also pH.

anaerobic Pertaining to the absence of free oxygen. Organisms that can grow without oxygen present.

anaerobiosis Life in an environment without oxygen or air.

anterior Toward the front.


bedding Moisture-retaining medium used to house worms.

biodegradable Capable of being broken down into simpler components by living organisms.

biological control Management of pests within reasonable limits by encouraging natural predator/prey relationships and avoiding use of toxic chemicals.

biomass That part of a given habitat consisting of living matter, expressed as weight of organisms per unit area. Recommended biomass of worms for vermicomposting is about one pound per square foot surface area of bedding.

breeders Sexually mature worms as identified by a clitellum.

buccal cavity The mouth cavity.

buffer A substance which renders a system less sensitive to fluctuations between acidity and alkalinity. Humus serves as a buffer in soil.


calciferous glands Glands within the worm mouth that produce a calcium carbonate substance that enables the worm to expel “sheathed castings.”

calcium carbonate Used to reduce acidity in worm bins and agricultural soils. See lime.

castings See worm castings; vermicast.

cellulose An inert compound containing carbon, hydrogen and oxygen which is a component of worm beddings. Wood, cotton, hemp and paper fibers are primarily cellulose.

chlorosis Abnormal yellowing of plant tissues caused by nutrient dificiency or activities of a pathogen.

cerebral ganglion A collection of nerve cells that serve as the brain for a worm.

clitellum A swollen region containing gland cells which secrete the cocoon material. Also called girdle or saddle.

cocoon Structure formed by the clitellum which houses embryonic worms until they hatch.

coelomic fluid A fluid that is expelled through the anus of the worm in times of stress.

compost Biological reduction of organic wastes to humus. Used to refer to both the process and the end product. One composts leaves and garden residues to obtain compost which enhances soil texture and fertility when used in gardens.

consumer An organism that feeds on other plants or animals.

crop Digestive organ in the anterior part of a worm consisting of a thin-walled sac just behind the esophagus.

culture To grow organisms under defined conditions. Also, the product of such activity, as a bacterial culture.


decomposer An organism that breaks down cells of dead plants and animals into simpler substances.

decomposition The process of breaking down complex materials into simpler substances. End products of much biological decomposition are carbon dioxide and water.

dorsal The underside of the worm.

dorsal blood vessel The blood vessel on the underside of the worm.


earthworm A segmented worm of the Phylum Annelida, most of whose 4400 species are terrestrial.

egg A female sex cell capable of developing into an organizsm when fertilized by a sperm.

egg case See cocoon.

Eisenia andrei Scientific name for worm commonly used for vermicomposting. Eisenia andrei is a close relative of Eisenia fetida. It is entirely reddish, does not appear striped and is sometimes known as the “reg tiger” worm.

Eisenia fetida Scientific name for the most common redworm used for vermicomposting. It is characterized by lack of pigment between its reddish segments, thus showing a striping pattern. Some common names include tiger worm, manure worm and brandling.

enchytraeids Small, white, segmented worms common in vermicomposting systems.

enzyme Complex protein which provides a site for specific chemical reactions.

esophagus A tube through which food passes from the pharynx to the crop, then gizzard of the worm.

excrete To separate and to discharge waste.


feces Waste discharged from the intestine through the anus. Manure.

fertilize To supply nutrients to plants or to impregnate an egg.


gestation That span of time from fertilization and egg formation to worm hatchlings emerging from the cocoon.

girdle See clitellum.

gizzard Region in anterior portion of digestive tract whose muscular contractions help grind food.

grit Coarse or fine abrasive particles used by worm in gizzard to grind food.


hatchlings Worms as they emerge from a cocoon.

hemoglobin Iron-containing compound in blood responsible for its oxygen-carrying capacity.

hermaphrodite Term for an organism which possesses both male and female sex organs. Most worms are hermaphrodites (some are parthenogenetic, that is, have only female sex organs).

humus Complex, highly stable material formed during breakdown of organic matter.

hydrated lime Calcium hydroxide. Do not use in worm bins. See also lime.


inoculate To provide an initial set of organisms for a new culture.


leach To run water through a medium, causing soluble materials to dissolve and drain off.

leaf mold Leaves in an advanced stage of decomposition.

lime A calcium compound which helps reduce acidity in worm bins. Use calcium carbonate, ground limestone rock, egg shells or oyster shells. Avoid caustic, slaked and hydrated lime.

litter (leaf) Organic material on forest floor containing leaves, twigs, decaying plants and associated organisms.

loam A mixture of clay, sand and organic matter that produces a rich soil.

lumbricus rubellus Scientific name for a worm species found in compost piles and soils rich in organic matter. Sometimes known as red marsh worm, dung worm or redworm.


microbes Very minute living things, whether plant or animal; bacteria, protozoa, fungi, actinomycetes.

macroorganism Organism large enough to see by naked eye.

microorganism Organism requiring magnification for observation.

mold A furry growth on moist decaying organic material, usually a fungus.

monoculture Cultivation of a single species.

mucus A slimy secretion of the mucus membranes that coats and protects, as in the lining of the lungs.


nematodes Small (usually microscopic) roundworms with both free-living and parasitic forms. Not all nematodes are pests.

nephridia Pertaining to the urinary excretion of the worm.

nutrient A life sustaining substance.


optimal Most favorable conditions, such as for growth or for reproduction.

organic Pertaining to or derived from living organisms.

overload To deposit more garbage in a worm bin than can be processed aerobically.

ovum A mature female cell, after fertilization, which can develop into a member of the same species.


parthenogenic The reproduction and the development of a species by an unfertilized ovum, as in some species of worms.

pasteurize To expose to heat long enough to destroy certain types of organisms.

peat moss Sphagnum moss which is mined from bogs, dried, ground and used as an organic mulch. Although acidic, its light, fluffy texture and excellent moisture retention characteristics make it a good medium for shipping worms. No longer recommended as a worm bedding because it is a limited resource and suitable alternatives exist.

percolate A liquid passing through a porous space.

perlite A lightweight volcanic glass used to increase aeration in potting mixtures.

pH An expression for degree of acidity and alkalinity based upon the hydrogen ion concentration. The pH scale ranges from 0 to 14; pH7 being neutral; less than 7, acid; greater than 7, alkaline.

pharynx Muscular region of the digestive tract immediately posterior to a worm’s mouth.

porosity Permeability by water.

posterior Toward the rear, back or tail.

pot worms See enchytraeids.

prostomium Sensitive fleshy lobe protruding above the mouth.

protein Complex molecule containing carbon, hydrogen, oxygen and nitrogen; a major constituent of meat. Worms are approximately 60% protein.

protozoa Microscopic animals.

putrefaction Anaerobic decomposition of organic matter, especially protein, characterized by disagreeable odors.


redworm A common name for Eisenia fetida, Eisenia andrei and also Lumbricus rubellus. Eisenia fetida and Eisenia andrei are the primary redworms used for vermicomposting.

regenerate To replace lost parts.


saddle See clitellum.

salt Salts are formed in worm bins as acids and bases combine, having been released from decomposition of complex compounds.

secrete To release a substance that fulfills some function within the organism. Secretion of slime by a worm helps retain moisture and protect its body from injury by coarse soil particles.

segment One of numerous disc-shaped portions of a worm’s body bounded anteriorly and posteriorly by membranes.

seminal fluid Fluid which contains sperm that are transferred to a worm’s mate during copulation.

setae Bristles on each segment used in locomotion.

sexually mature Possessing a clitellum and capable of breeding.

side dressing Application of nutrients on soil surface away from stem of plants.

slaked lime Calcium hydroxide. Do not use in worm bins.

slough To glide or slip off, as in a cocoon sliding over the worm head.

species Basic category of biological classification, characterized by individuals which can breed together and produce offspring which can also produce young.

sperm Male sex cells.

sperm-storage sacs Pouches which hold sperm received during mating.

subsoil Mineral-bearing soil located beneath humus-containing topsoil.


taxonomist A scientist who specializes in classifying and naming organisms.

top dressing Nutrient-containing materials placed on the soil surface around the base of plants.

toxic Poisonous, life-threatening.

toxoplasmosis Disease caused by the protozoan Toxoplasma gondii.


ventral Pertaining to the top of the worm body.

vermicast A single worm casting or a quantity of worm castings. Worms “work” material by ingesting, excreting and re-ingesting it. Vermicast is extensively worm-worked and re-worked. It may be overworked and has probably lost plant nutrients as compared to vermicompost. Vermicast has a fine, smooth texture which may dry with a crust on the surface. See also worm casting.

vermicompost Mixture of partially decomposed organic waste, bedding and worm castings. Contains recognizable fragments of plant, food or bedding material as well as cocoons, worms and associated organisms. As a verb, to carry out composting with worms.

vermicomposting The process of using worms and associated organisms to break down organic waste into material containing nutrients for plant growth.


white worms See enchytraeids.

worm bin Container designed to accommodate a vermicomposting system.

worm castings Undigested material, soil and bacteria deposited through the anus. Worm manure. See also vermicast.

worm tea A liquid fertilizer made from worm castings, which can be used on indoor and outdoor plants, trees and shrubs.