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Vermicompost (also called worm compost, vermicast, worm castings, worm humus or worm manure) is the end-product of the breakdown of organic matter by some species of earthworm. Vermicompost is a nutrient-rich, natural fertilizer and soil conditioner. The process of producing vermicompost is called vermicomposting .

The earthworm species (or composting worms) most often used are Red Wigglers (Eisenia foetida) or Red Earthworms (Lumbricus rubellus). These species are commonly found in organic rich soils throughout Europe and north America and especially prefer the special conditions in rotting vegetation, compost and manure piles. Composting worms are available from nursery mail-order suppliers or angling (fishing) shops where they are sold as bait. Small-scale vermicomposting is well-suited to turn kitchen waste into high-quality soil, where space is limited.

Together with bacteria, earthworms are the major catalyst for decomposition in a healthy vermicomposting system, although other soil species also play a contributing role: these include insects, other worms and molds.

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  Vermicomposting bins (also known as worm bins) vary drastically depending on the desired size of the system. Garden-scale containers can be made out of bricks arranged in the shape of a box. Bins for an apartment or similar dwelling can be anything from reused plastic buckets to purpose-built commercial containers.

Small scale

Small-scale systems may use a wide variety of bins. Often, small-scale composters build their own bins. Companies also sell such bins. Commonly, bins are made of old plastic containers, wood, Styrofoam containers, or metal containers.

Some materials are less desirable than others in bin construction. Styrofoam is believed to release toxins into the earthworms' environment[citation needed]. Metal containers often conduct heat too readily, are prone to rusting, and may release heavy metals into compost.

Bins should have holes in the sides to allow air to flow, and a spout that can be opened or closed or holes in the bottom to drain into a collection tray. Plastic bins require more drainage than wooden ones because they are non-absorbent. The design of a small bin usually depends on where an individual wishes to store the bin and how they wish to feed the worms. Most small bins can be grouped into three categories:

  • Non-continuous – an undivided container. A layer of bedding materials is placed in the bin, lining the bottom. Worms are added and organic matter for composting is added in a layer above the bedding. Another layer is added on top of the organic matter and the worms will start to compost the organic matter and bedding. This type of bin is often used because it is small and easy to build. But it is relatively difficult to harvest because all the materials and worms must be emptied out when harvesting.
  • Continuous vertical flow – a series of trays stacked vertically. The bottom-most tray is filled first, in a similar fashion to any other bin, but is not harvested when it is full. Instead, a thick layer of bedding is added on top and the tray above is used for adding organic material. Worms finish composting the materials in the bottom tray and then migrate to the one above. When a sufficient number of worms have migrated, the vermicompost in the bottom tray can be collected and should be relatively free of worms. These bins provide an easier method of harvesting.
  • Continuous horizontal flow – a series of trays lined horizontally. This method too relies on the earthworms migrating towards a food source in order to ease the process of harvesting. The bin is usually constructed to be similar to a non-continuous bin but longer horizontally. It is divided in half, usually by a large gauge screen of chicken wire. One half is used until it becomes full, then the other half is filled with bedding and organic matter. In time, the worms migrate to the side with the food and the compost can be collected. These bins are larger than a non-continuous system but still small enough to be used indoors, with the added bonus of being easier to harvest.

Large scale

  There are two main methods of large-scale vermiculture. Some systems use a windrow, which consists of bedding materials for the earthworms to live in (see bedding below) and acts as a large bin; organic material is added to it. Although the windrow has no physical barriers to prevent worms from escaping, in theory they should not due to an abundance of organic matter for them to feed on. Often windrows are used on a concrete surface to prevent predators from killing the worm population. When large scale windrows are fed on one side consistently, a wave motion is generated over time.


Starting off



















Bin Maintenance




The pH should be slightly alkaline. Alkalinity can be increased by occasionally adding a handful of calcium carbonate, sold as "garden lime." Do not confuse calcium carbonate with regular lime (Calcium oxide), which is far too alkaline and will kill worms. Adding many citrus peels can hinder the worms, but probably due not to acidity but to d-limonene, a fragrant chemical present in the rind of citrus fruits.[2] Coffee grounds have sometimes been blamed for acidity, but analysis shows they are only mildly acidic, with a pH of 6.2.[3]


There are two methods of adding matter to the bin.






Vermicompost properties


Vermicompost benefits soil by

  • improving its physical structure;
  • enriching soil in micro-organisms, adding plant hormones such as auxins and gibberellic acid, and adding enzymes such as phosphates and cellulase;
  • attracting deep-burrowing earthworms already present in the soil;
  • improving water holding capacity;
  • enhancing germination, plant growth, and crop yield; and
  • improving root growth and structure.



Vermicompost fed to poultry stimulates their immune system[4].





See also

Sustainable development Portal

Commercially available vermicomposting systems

Home vermicompost systems or worm bins are available from many retailers. Clive Roberts BSc invented the very first 'Wormery' in the late 1980s and in 1991 patented his design for The Original Wormery, in the UK.

In the United States, state Cooperative Extension Services and local governments may provide assistance and training in home vermicomposting.


  1. ^ Richard, Tom; Nancy Trautmann. C/N Ratio. Cornell composting: composting in schools. Cornell university college of agriculture and life sciences. Retrieved on 2007-07-29.
  2. ^ In her book, Worms Eat My Garbage, (Kalamazoo, MI: Flower Press, 1997), p. 64, pioneering vermicomposter Mary Appelhof says that another science teacher's ninth-grade student did a science project that identified limonene as the toxin. Appelhof was skeptical but realized that the student probably had a parent who worked at a nearby Dupont Chemical Company research facility with the ability to do the tests.
  3. ^ Soil and Plant Laboratory Inc., Bellevue, WA. (2005). The Starbucks coffee compost test. Sunset magazine. Retrieved on 2007-07-29.
  4. ^ J.L. Spencer, J.R. Chambers, and H.W. Modler: Avian Pathology, v.27 no. 3, June 1998, Competitive exclusion of Salmonella typhimurium in broilers fed with vermicompost and complex carbohydrates, pg 244.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Vermicompost". A list of authors is available in Wikipedia.