Worm farming knowhow

Creating the perfect habitat for your red wigglers will mean lots of compost in your future. Your garden will thank you, and so will Mother Earth.

by Gale Beeby

The worms

Red wigglers (also known as red worms, compost worms or manure worms) are the best worms for your compost bin. They love to gorge on leaf litter, food scraps and other organic material. They reproduce quickly – if you notice yellowish rice-like pellets in your compost, that’s their cocoons – and can double in population in just a few months. The easiest way to obtain worms is from someone who already has an established worm farm, but you can usually purchase them at bait shops or online.

The bin

Almost anything can be used as a bin and a cheap choice is an opaque plastic storage bin with a lid. Another popular choice is a blue recycling bin, which some municipalities equip with a lid. The worms do not like sunlight, so avoid any transparent materials. The lid is vital in preventing fruit flies, fungus gnats and other pests from taking up residence in your bin.

You will need to make sure that air can get into your bin, so drill 10 to 12 holes, 1cm in diameter, in the lid. This will also help manage excess moisture or humidity. You may also drill holes on the bottom of the bin to allow water to drip out, but make sure to add a piece of screen to line the bottom of your bin to contain the compost and prevent any worms from escaping. You can dilute this water – known as worm tea – and use it as a fertilizer before your compost is even ready.

Bin size and worm quantity

Generally, a bin with a larger surface area is preferred over a deep container as red wigglers prefer to be above ground with the leaf litter and other refuse. Food scraps spread over a larger area will be processed more quickly.

Choose a bin that suits the amount of food scraps your household produces. Environment Ontario suggests that one to two people will likely need about .5kg of worms in a bin that is 30cm high by 45cm in length and 60cm wide. Two to three people will need 1kg of worms in a bin that is 30cm by 60cm by 60cm, while a larger family of four to six people will need 2kg of red wigglers and a bin that is 30cm by 60cm 105cm.

The bedding

The red wiggler will eat the equivalent of its own body mass each day, but only half of that comes from the food scraps. The other half is from the bedding. As with any compost, you need to balance the nitrogen to carbon ratio. Since most of the added scraps are rich in nitrogen, you will need to make sure the bedding is high in carbon. Great bedding choices include leaves – which can be collected in the fall – coconut husks, finely chopped straw, peat moss and shredded paper (without coloured ink) or cardboard. It is best to use three or four different materials, as well as a few fistfuls of sand or potting soil, which the worms use to help digestion.

Bedding should be moist, but not soggy. After an initial watering, you probably won’t need to add water again as the decomposition process produces moisture. You may, in fact, have to add more dry bedding material as time goes on.

A spot for your bin

Most people store their bins under the kitchen sink, in the garage or in the bathroom. The worms will be happiest between the temperatures of 17C to 22C but can do well in cooler or warmer temperatures as long as the thermometer doesn’t dip below 4C.

Feeding your worms

Feed your worms one to three times a week and in between feedings store your scraps in a container with a tight lid. Letting the scraps sit for a few days allows a buildup of microbial activity and this is what the worms actually consume. For the same reason, when building your initial set-up, you may add the bedding and the scraps days before adding the worms.

The smaller the scraps, the more rapidly they’ll break down. Feed a different area of the composter each time and devise a rotation schedule and stick with it.

Food scraps to include:

• Fruit and vegetable scraps

• Unprocessed hair (chopped finely so the worms do not become entangled)

• Plant trimmings become entangled)

• Coffee grounds and tea bags

• Plant trimmings

Problem items:

• Meat and fish

• Dairy products

• Onions or garlic

• Oils and fats

• Sauces, dressings and vinegar

• Salts (if you hae a water softener, do not use this water in your bin)

• Pet and human waste

Take care to moderate the amount of citrus fruit peelings and coffee grounds that go into the bin due to their acidity. Adding crushed eggshells every week or so will help balance the pH level and provides the worms with calcium, which is needed to produce cocoons. You can include cooked pasta, rice, bread and beans that do not have any added salt, oils, sauces or dressings.


About every three months, you will need to harvest your compost. You’ll know it is ready when it is uniform in colour and texture – it will look like a dark, crumbly soil. This finished compost is mainly composed of worm castings and some partly decomposed materials. You can safely handle the castings with your bare hands as they are non-toxic to people and pets.

To harvest, shine some light on the bin (or put it in the sunlight) and wait a few minutes. The worms will move away from the light and you can skim the compost off the top. You will need to repeat this process a few times. Then add some fresh bedding and food scraps and return any wayward worms and cocoons to your colony.

Using your compost

Here are a few suggestions for putting the compost to good use:

• Mix it with soil for starting seeds or for potted plants (one part compost to 10 parts soil).

• Work it directly into the soil of your vegetable gardens or flowers beds.

• Use it for your transplants by adding some to the bottom of the hole before replanting.

• Spread it beneath your trees and shrubs to give them an extra boost.

• Sprinkle it on your lawn for naturally healthy grass.

• Make a compost tea by adding ¼ cup of vermicompost to two litres of water and let it sit for 24 hours and then use it to water plants and spray on leaves.

Source: The Canadian Wildlife Federation