by Adrian White
20 December, 2021 by
Lucija Johum

As an organic greenhouse grower, you’re probably passionate about using only natural methods, and without all those chemicals. You have natural pest repelling methods in place for your structure, and you most likely use natural fertilizers (like compost tea) to nourish your plants. Above all else, though, you want to expand your horizons and possibilities, like every good grower out there.

Maybe you’re certified organic, or maybe you’re not. Or maybe you’re completely new to all these above-mentioned methods, but want to give them a try nevertheless. Regardless, there are countless fascinating paths that gardeners and farmers – whether natural growers or not – can walk down and explore to keep their business ahead of the curve.

One of the most exciting, popular, and proven-to-be-useful methods in organic growing is vermicomposting, also known as vermiculture (“vermi-” meaning worm in Latin). It’s a combination of composting with the fascinating soil powers of earthworms; particularly their ability to transform your waste stream into incredibly nutrient-rich, completely broken down natural fertilizer. Best of all: it costs practically nothing.

It’s a well-known fact that earthworms are great to see in your garden. Move them to the compost pile, and you bring their magic straight to your growing operation. All sorts of growers, from the humblest gardeners to the most advanced greenhouse-operating farmers, have adopted earthworms as unofficial mascots – or even pets – in addition to hiring them as enthusiastic workers for their plants’ well-being and nourishment.

Anyone can harness their powers, work with mother nature, and see amazing impacts on their plants – including you.


One reason why vermicomposting (also called “worm farming”) has become so popular: it’s not rocket science, and it’s quite easy to learn. Anyone can make their own worm farm with the right materials, know-how, and finesse. All you need is the right container, the right worms, and pretty much the same scraps (though not all) that you would have put in your regular compost pile.

Within your container, you introduce your worms, throw in the scraps, and watch the magic happen. Your earthworms consume organic matter and expel it in the form of nutrient-rich, microbially-active soil-like worm leavings, more commonly called castings. These are lighter in form than typical compost, and get created much quicker – and during this whole process, the tunneling and wriggling of your worms aerates the organic matter, making it biodegrade even faster on a whole other level.

As you would take care of any pet, however (remember that earthworms are living critters after all), you’ll have to make sure that you’re feeding and even watering them right. Gentle care and consideration is needed, too. The end result: amazing compost and natural fertilizer right in your backyard, or conveniently right next to your operation, straight from your waste stream and at a faster pace than regular compost (and at practically no price).


The typical methods of composting, without earthworms, are intensive. Layering of various materials is important for proper natural biodegradation. Even more vital is the aeration required for quick, timely transformation of organic materials into finished, usable compost to be integrated as a soil medium and fertilizer in one’s garden or farm. 

Vermicomposting helps you circumnavigate a lot of these requirements. In comparison, it gives you a leg up in the composting world, and for a number of very good reasons:

  • It speeds the composting process. Earthworms catalyze aeration, microbial colonization, and material breakdown by tunneling and consuming compost quickly.

  • It saves your back some labor. By doing what they do (naturally), worms accomplish the tough work of turning and aerating compost for you.

  • It’s more nutrient-rich. According to Lowenfels and Lewis of Teaming With Microbes, matter that passes through worms is 50% higher in organic material than matter that is not consumed, and chock-full with way more nutrients.

  • It’s more microbially-rich. Worms impart their own digestive enzymes in their castings, which attract more life and microbes (thus more nutrients).

  • You work with nature. Get the intangible satisfaction of working in harmony with nature’s amazing powers – rather than against them.


Comparable to traditional composting, vermicompost comes with only a handful of simple steps. The key to success is following these to a T without much deviation, while keeping in mind that you’re working with living things. Earthworms are hardy creatures however, and they don’t need much – just your scraps, your awareness, a good spot, and some delicate handling.

1. Select the Right Worms

While capturing worms from your neighboring fields is one way to do it, it should be known that not all varieties of worms are the best natural “workers” for the vermicompost pile. You’ll want to show favor to certain varieties, which may even lead you to buying your first bunch, which is possible online. Red Wigglers are one very popular type for worm farms, as well as Tiger worms – both are avid tunnelers and consumers.

2. Find (Or Build) The Right Container Home

The container home you choose for your worms can vary from being just a few gallons big to dozens of gallons big, depending on your greenhouse or operation size. Regardless of size, be picky about materials, and only choose ones that would be safe for your worms: stainless or galvanized steel, plastic (make sure it’s food safe and withstands sunlight and heat), and ceramic all work well. Pre-made worm farm containers and kits are also easy to find online.

Especially avoid any materials that are black in color. While this can be helpful keeping your worm farm warm during winter, it can cause worm death from overheating in the summer. If going for a large worm farm (3 by 3 feet or larger), wood is acceptable, though make sure it is untreated and placed outside, not indoors – and avoid waterlogging which can cause rot and smell.

All worm farm containers should come with a lid, a drain tray for the container to sit in, and holes drilled or built into the lid, bottom, and sides of the container, whether you build it or buy it.

3. Choose a Good Location

Indoors or outdoors – and even inside your greenhouse – works well. During a hot summer, however, vermicompost in your greenhouse can become overheated. If your setup is small and movable enough, favor spots that get shade, such as up against the north-facing side of buildings, sheds, and structures. Generally speaking, keep clear of areas that would get excessively hot, dry, or inversely, cold and excessively damp.

Having your setup located outside is often the least problematic: drainage and moisture issues, smell, and even stray compost from transporting will then not be a problem. In cold climates, however, this means you’ll have to keep your vermicompost alive and warm. This can be achieved by placing your farm on the south-facing side of a building or structure through winter, and covering it with a black cloth during the day and insulation at night.

4. Prepare Container and Introduce Worms

To prepare for receiving your worms, you’ll want to line your container with a carbon or “brown” material (to use a common composting term). This can be anything from shredded paper or newspaper (untreated) to dried leaves or light wood chips or shavings (also untreated and chemical-free). Make sure that the whole bottom of the container is covered – having the farm filled up about 1/3 of the way with this lining is desirable.

Atop this lining, place a good handful of organically-rich and microbially-active soil or finished compost. It’s good to make sure this soil is on the damp side – give it a spritz of water if need be, but don’t waterlog it. Then, you are ready to introduce your worms.

5. Start Composting

The rest is cake: toss your scraps on the top of this setup in your container, as you would with your typical compost pile. Cover any fresh matter with a sprinkling of brown matter (shredded paper, newspaper, dried leaves, wood chips/shavings, all chemical free of course) to keep down smell, bugs, and to catalyze breakdown. When not actively in use, keep your container with worms in it shut for their protection, and to also keep things dark and damp the way they like it.


One aspect that sets worm composting apart from typical methods: you can’t feed them everything. Some scraps they will consume quickly, and some are good for them; others can bring them harm, or they may not touch them at all. In that case, it is often wise to have a compost pile reserved for your non-worm waste.

What Worms Will Eat:

  • Coffee grounds

  • Dead plants and flowers (non-toxic)

  • Dried leaves

  • Egg shells

  • Fruit (non-citrus)

  • Grass clippings (seedless)

  • Harvested plant matter

  • Human hair, pet hair, or lint

  • Nutshells

  • Rice, pasta, non-dairy baked goods

  • Tea bags

  • Untreated paper scraps

  • Untreated wood chips and shavings

  • Vegetable scraps

What Will Harm Worms (Or What They Won’t Eat):

  • Avocado rinds

  • Bones

  • Cat litter

  • Citrus rinds

  • Dairy products 

  • Meat

  • Pet feces

  • Pickled foods/vinegar

  • Plastic or other man-made materials

  • Sand

  • Oils, fats, or grease

  • Wood or charcoal ash

As a side note: avoid feeding your worms any matter from your garden, field, or farm like diseased plant scraps or seedy weeds. These will transfer disease and weeds to your growing operation of you use your worm castings on it. If you wish to feed weed scraps to your pile, make sure they are seed-free, disease free, and edible to your worms.


The most work you’ll do with vermiculture: feeding your worms and removing castings once they have built up. The rest of the process, you can sit back and watch your worms munch away, and do the work that they are more than happy to do. Depending on the matter you feed them, the very start of your pile should yield you usable castings within 1 to 2 weeks.

Once the majority of matter – both fresh and brown – has broken down, disappeared, and turned into castings, you can remove this dark, rich, humus-like compost and store it for future use separately. Leave some in there at the bottom (along with your worms, of course) and then re-line your farm with fresh carbon matter. Then you start from the beginning: add fresh material, cover with carbon, and watch it break down.

Use your new castings much like you would use broken down compost from a typical pile. Mix some of it in soil mix for starts, transplants, container plants, and more; amend it into beds and fields; side-dress established, mature plants with it around their roots; or use it to brew powerful, nutrient-rich, and active compost teas.


How does a worm farm fit into the greenhouse world? It’s not much of a stretch, and it doesn’t require changing the way you go about it too much. Anyone who runs a greenhouse operation – whether as a hobby or a business, large or small – can incorporate the benefits of incredible worm castings to nourish their crops.

Particular to greenhouse setups and systems, however, here are a few useful tips:

  • Avoid placing your farm in a greenhouse during summer. Unless you have ways to fine-tune and regulate temperature, this can be detrimental to earthworm well-being (they prefer shade and damp).

  • If you can, move your setup into a greenhouse during winter. This helps keep them warm during cold months. Make sure to keep them out of direct light, which can harm them on unseasonably warm days.

  • Place them on the north-facing side of your greenhouse in summer. If you prefer to keep your farm outdoors (but nearby) or have a larger setup that can’t be transported/moved indoors, the north-facing side of your greenhouse will cast shade to keep them cool in the heat.

  • Place them on the south-facing side of your greenhouse in winter. This will ensure that they get some warmth and sunlight. Try covering the container with an insulated blanket during nighttime, or give them a black cover during the day.

  • Replace fertilizers with worm castings. Regularly amend or cut your soil mixes with worm castings, at least once per year. This will help replace lost nutrients over time and restore the microbial life that may have been lost there over time – especially if you use chemical fertilizers or repellents.


When you have vermiculture as an option, don’t let the limitations of typical composting hold you back. While traditional methods are useful, they do take much longer (and more work) to produce usable matter. 

For the busy greenhouse grower, incorporating vermiculture can be a smart solution: it takes less work, creates richer compost fertilizer, and takes much less time to have ready-to-use castings for the benefits of your plants.

Lucija Johum 20 December, 2021
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