Do you want to do vermicomposting on a large scale? If YES, here is how much it would cost to do vermicomposting and the problems you will face. Vermicompost, or castings, is worm manure. Worm castings are regarded by many in horticulture as one of the best soil amendments available. Note that the nutrient content of castings tend to largely depend on the material fed to the worms—and worms commonly feed on highly nutritious materials, such as food waste and manures.

Worm castings offer a wide range of nutrients helpful to promote plant growth and in a form readily available for plant uptake. According to experts, the biology of the worm’s gut facilitates the growth of fungus and bacteria that are beneficial to plant growth. Also, a lot of chemical compounds are found in castings that are believed to promote plant growth.

Note that most of the content of worm castings and their effects on plants are still being studied. However, farmers and soil blenders concur with the benefits of worm castings on their effect on plants, even when the worms are fed low-nutrient materials such as paper fibre.

Types of Worms Used for Vermicompost

According to reliable reports, most worm farms raise two main types of earthworm: Eisenia foetida and Lumbricus rubellis. These worms are commonly used to produce vermicompost, as well as fish bait. These worms are referred to by a variety of common names, including red worms, red wigglers, tiger worms, brandling worms, and manure worms.

Sometimes these two species are raised together and are difficult to differentiate, though they are not believed to interbreed. Worms are known to survive a wide variety of temperatures, but they thrive best at temperatures between 55 and 77 degrees Fahrenheit (13–25 degrees Celsius).

These organisms need a moist, organic substrate or “bedding” in which to live. They will eat the bedding and convert it into castings along with other feed. Moisture and oxygen are very imperative and bedding should be about as damp as a wrung-out sponge. Also remember that a worm’s skin is photosensitive and therefore they need a dark environment.

Since worms do not have teeth, they always need some type of grit in their bedding that they can swallow and use in their gizzard to grind food, much like birds do with small stones. A little soil or sand will work, but it should be sterile so that no foreign organisms are introduced. Common additives used include rock dust or oyster flour (ground up oyster shells).

Also note that since oyster flour is basically calcium carbonate, giving the worms too much will raise the pH in their environment. Worms are known to prefer a slightly acidic pH level of about 6.5. For a typical worm bin, no more than a tablespoon of grit is needed, which should not significantly alter the pH.

They will eat a wide variety of organic materials such as paper, manure, fruit and vegetable waste, grains, coffee grounds, and ground yard wastes. Although worms will eat meat and dairy products, it is best not to feed these materials or oily foods to worms, due to potential odour and pest problems.

Worms also consume limited amounts of citrus scraps, but limonene, a chemical compound found in citrus, is toxic to worms, so it is best to limit or avoid feeding them this material. Their food is also expected to be small enough to swallow, or soft enough for them to bite. Some foods may not be soft enough initially for them to consume, but they quickly degrade so that the worms can consume them.

3 Main Methods of Large Scale Vermicomposting

Large scale vermicomposting is practised in developed countries like Canada, Italy, Japan, Malaysia, the Philippines, and the United States. There are three main methods of large scale vermicomposting.

1. Windrow System of Earthworm Farming

In this method of Vermicomposting, windrows tend to be constructed on a concrete surface. It may be in a pit or may be on soil surface. Windrows are linear piles on the ground containing feed-stocks up to 3 feet high. If the floor is made up of cement, then earthworm bed will be prepared with soil, straw, leaves, ferti­lizer, etc.

They are being used extensively both in the open and under cover, but needs either a lot of land or large buildings. Note that during composting process the whole pile is covered by a PVC sheet to prevent predators and environmental hazards. This Vermicomposting method is used for the production of compost by piling organic matter or biodegradable waste, such as animal manure and crop residues, in long rows (windrows).

2. Raised Bed Earthworm Farming

In this method of Vermicomposting, soil of the floor tends to be raised with the help of axes to prepare a bed. Bedding is any material that provides a relatively stable habitat to worms. Good bedding for vermicompo­sting is expected to have:

  • High Absorbency

As worms’ breath through skin, the bedding should be able to absorb and retain adequate water.

  • Good Bulking Potential

It is the property which ensures proper oxygen supply to the worms.

  • Low Nitrogen Content (High Carbon: Nitro­gen Ratio)

Although worms consume their bedding as it breaks down, it is very important that this be a slow process. High protein/nitrogen levels can result in rapid degradation and associated heating may be fatal to worms.

3. Flow through System of Earthworm Farming

Note that this method is ideal indoor facilities. In indoor spaces, the concrete surface is constructed in the pit to prevent predators gaining access to the worm population. The dimension of the pit should be 3 feet x 8 feet. The feed is initially dumped in one corner of the pit.

Note that the worms are intro­duced into the pile of the feed and kept for some days. Morning or evening is the best time to add worms. The lengthwise direction of the earthworm beds and their shelters should parallel the prevailing winds.

How to Do Vermicomposting on a Large Scale

  1. First decide how large you want your business to be. Are you more comfortable starting small and then growing up your worm farm? Is there room in your backyard for a large operation? If your business grows, is your property zoned to accommodate the growth?
  2. Choose where to place your worms on your property; near a water source, near electricity, or maybe in a shed. What is the best place considering the climate fluctuation in your area? Where will the beds be easy for you to tend, considering your back health and height)?
  3. Locate a supplier that can provide enough bedding and stock for an operation of your size. Do you have a horse ranch or paper Mill close to you? Be aware that when acquiring manure you must ask what if any de-worming medications are given to the providing animals. These medications can and will also kill your worms.
  4. Acquire the proper tools; a pitchfork, pH meter, compost thermometer, hand claw garden tool, and a shovel. A paper shredder will prove convenient if you decide to use paper as your bedding source.
  5. Red worms need just one square foot of surface area for every pound of worms. Most worm growers estimate there are approximately 1,000 adult red worms in a pound. But, this isn’t a figure you need to know, because commercial worm growers only sell their worms by the pound.
  6. You will have to build or buy commercial bins, or build windrows, to accommodate the quantity of worms you decide to grow. Windrows are worm beds that are in the ground. Many worm growers prefer this type of bed because they feel it produces a better, bigger and healthier worm. These beds generally have very good drainage and aeration, and the food is in good supply. And if the conditions get out of control, the worms can migrate to another location within the bed until the proper conditions are available again.
  7. Get hold of the bedding and feedstock: the organic material that is fed to worms. Take care of any preparation of that material that is necessary. Are you shredding newspaper or leaching manure?
  8. Buy your worms. Always be certain that everything is prepared for the worms before they arrive! Know the scientific name of the worms you have decided to grow.

How to Separate Worms from Castings

The trickiest part in Vermicomposting is separating the worms from the casting. You want to keep your worms in the worm farm. There are a few techniques for harvesting worm castings which allow you to separate the worms out.

i. The ‘Rainy Day technique’

If your farm uses stacked trays, you can wait for a day when it looks like it is about to rain. On rainy days the barometric pressure in the atmosphere drops, and the worms sense this, so they move to the top to avoid drowning when the rain comes down.

Note that this is a natural survival instinct for when the rain floods their burrows and tunnels in the ground. When the worms come to the top, they will all leave the lower tray, and will gather in the top tray or inside of the lid.

When they all come up, you can carefully lift out the lower tray and put it aside for later use. Remember not to leave it out in the rain though, as it will become overly waterlogged, and lots of beneficial bacteria will get washed out, put it undercover somewhere and use it in the garden as soon as possible after the rain has passed.

ii. The ‘Pyramid technique’

Worms are known to dislike light, so make sure you don’t expose them to direct sunlight when caring for them, they sunburn easily! To separate the castings from the worms, gather your castings, which will contain worms, wear to a pyramid shape.

Remember to only do this in a shady spot outdoors. The worms will not stay in the narrow pointed tip, and will burrow downwards to escape the light. Then carefully scoop off the tip of the worm casting pyramid, and put that into a bucket.

Then reshape the pile into a pyramid with a new tip, and harvest the worm-free castings again. Note that as you keep on doing this, the pyramid will get smaller and smaller, and the worms will keep moving to the bottom. When you have a small, low, flat pile full of worms, put it back in the worm farm.

iii. The ‘Let The Worms Decide technique’

Note that when their bedding turns to castings, they will be basically living in their own waste, which is not their preferred environment. Worms have a preference for fresh bedding material with a supply of food.

If you push the castings to one side of the worm farm to make a space to put in fresh bedding material, put fresh bedding in that space, and only lay food on the fresh bedding side, the worms will move over to the area with fresh bedding and food, and will move away from the side which contains only their waste (castings) and no food.

Immediately all the food is finished in the castings, they will decide to move out to the nicer side, and you can then collect the castings! This technique works well in long, wide worm farms such as bathtub worm farms.

4 Problems You Might Face in Your Worm Farm

Agreeably, worm farms are quite problem-free and easy to look after, but there are a few things to keep in mind that will make caring for your worm farm much easier.

a. Hot Weather

The easiest way to lose all the worms in a worm farm at once is to accidentally let them get cooked in hot weather. Sometimes, even the shadiest location might get direct sun exposure during summer, because the sun is directly overhead, or because the hot west afternoon sun comes in from the side as the sun lowers in the evening.

Worm farms can overheat simply due to the high temperature of a hot summer’s day, because the air outside is hot, and they’re in an enclosed container. To avoid this problem, prop the lid the worm farm open a bit to let air circulate through and to release any hot air that may be building up under the lid.

On very hot days, you may need to cool down the worm farm by watering it with a watering can and rainwater. The best way to protect worm farms from direct hot sun is to cover them with a screen of some sort that is light coloured and will reflect the sun, with sufficient air-space underneath it so it doesn’t trap the hot air over the worm farms and cause them to overheat.

b. Insects

Indeed it is natural to have a few other insects in your worm farm, but some are unwelcome guests! Ants do not belong in your worm farm. To discourage ants, dampen down the worm farm with a watering can full of rainwater, and to stop them getting in there, create a barrier, an ‘ant moat’ by sitting the legs of your worm farm (if it has legs) in tray of water.

Vinegar flies are also attracted to rotting food, especially fruit, as are fruit flies, so the best way to prevent them breeding is to cover the food scraps beneath a damp newspaper. Other insects such as millipedes are not really a headache; they are decomposers and feed on rotting organic matter, returning the nutrients to the soil.

Slaters, also known as wood lice, pill bugs, and roly-poly or butcher boys are also beneficial decomposers and are in fact land-based crustaceans! Soldier fly larvae, which look like giant silver-grey maggots are also beneficial, though they look a bit creepy.

c. Rain

Note that unless your worm farm is undercover, it will get rained upon, and some rainwater will get in, depending on the design. This is a benefit especially since it flushes out the castings and makes a good supply of worm casting leachate (worm wee) that you can use in your garden.

If your worm farm has a tap, and the tap is closed, then your worm farm may get flooded! The only solution is to leave the tap permanently open and place a small bucket underneath as shown below. This will also prevent the tap getting blocked too.

d. Smell & Odour

Have it in mind that a healthy worm farm will have little to no smell, maybe a faint but pleasant earthy smell just like healthy soil or a forest floor. If you perceive a sharp vinegar smell it may be too acidic, add crushed eggshells, garden lime, dolomite or wood ash to correct the problem.

But if it smells quite offensive, it is an indicator that the system has become quite anaerobic from too much uneaten food. You can fix this problem by not adding any more food, instead add a sprinkling of garden lime, dolomite or wood ash, and lightly stir up the existing food scraps to aerate them on a regular basis. Once the smell disappears, then begin feeding the worms again.

How Much Vermicomposting Cost in the United States

You can start for under $1,000 or as low as a couple hundred. After all, you only need the food, worms, dirt, and material. You don’t even have to bother about hiring any workers; the worms will work around the clock. Worms themselves can cost a fair amount of money, but again you don’t necessarily need to buy any.

Are there local gardening clubs in your area? If so, there is a good chance that one of their members would have composting worms and wouldn’t mind sharing some.

Aside from gardening clubs, you might ask around at local universities as well – not only are red worms often used for toxicology and composting research, but there are often environmental groups on campus that could help you get some starter worms. However, expect to spend on the following when looking to start this business.

  1. Worms: $70
  2. Dirt/Worm Bedding: $80
  3. Legal: $250
  4. Feed: $100
  5. Bin: $50
  6. Vermicast: $50

Total: $600


For so many years worms have been raised for fishing bait as well as a protein and enzyme source for various products, including animal food and biodegradable cleansers. Worms have also been used to manage agricultural wastes such as dairy manure.

They convert waste into worm manure (also known as worm castings), a nutrient-rich, biologically beneficial soil product. Vermicomposting just like it was stated above is the use of worms as a composting method to produce vermicompost. Vermiculture is worm farming for the production of worms.