- Wormery guide

Why a wormery is both a green and handy addition to the home

A wormery is a surprisingly tidy and efficient way to recycle your kitchen waste. More compact than most compost bins, a wormery can be kept inside your home. In addition, worms are fast workers and your waste is speedily converted into high quality compost (vermicompost). Most wormeries also have the added bonus of producing a nutritious liquid plant feed (leachate), also known as “compost tea”.

Like other methods of composting, recycling waste saves transport costs and reduces the methane produced by landfill sites. According to WRAP (Waste and Resources Action Programme), 6.7 million tonnes of food is wasted every year - that's about a third of the food we buy - making a startling impact on carbon emissions (see WRAP's website).

Composting at home is a crucial way to help the environment. But why would you bother with a wormery? You may have read up on the numerous benefits of composting, as discussed in our quick guide here, but what makes a wormery different?

What are the advantages of a wormery?

  • No garden space is required
  • It’s quick – worms are nature’s speediest composters, able to eat up to their own bodyweight of organic matter each day
  • No need to mix and turn waste
  • No odours and smells
  • Worms do the work themselves and require no maintenance
  • Worms operate effectively with small amounts of waste
  • A multi-tray system allows you to easily add scraps and remove compost
  • Add more food types such as cooked food – wormeries are sealed so they don't attract vermin
  • You get high-quality “vermicompost” as an end-product
  • Most wormeries also produce a liquid feed to give your plants and garden an extra boost

How does a wormery work?

The management and breeding of worms is known as vermiculture. Vermicompost, using worms for composting, is surprisingly easy: put them in place, and they get to work. Most worms in your garden are deep-burrowing and therefore not necessarily suited to wormeries. However, specialist composting worms feed on the food waste just below the surface. Therefore whether you are removing compost from the bottom or adding food to the top, you need never handle the worms.

Of the many species of worm, there are two types that are reliable and popular composters: Eisenia Fetida (also Red Tiger Worm, or Brandling) and Dendrobaena Veneta (also Dendra), also widely used as fishing bait. Despite the confusing names, these worms are easy to buy and will often come with a wormery. Use about 500g (approximately 1000 worms), or 1kg per cubic metre.

A simple, low-maintenance process

You can go on holiday for as long as a month and leave your wormery with no worries; simply add some food waste before hand and the worms will look after themselves. There is also no need to add or remove worms once you have set your wormery up: worms balance their reproduction depending on their conditions, so they will constantly adapt to the size of your wormery and the amount of waste you add.

Where should a wormery go?

Worms are similar to humans, working best at room temperature. Whether it’s near your back door, in your kitchen, or in a garden shed, your wormery should be kept between 10 and 25 degrees Celsius. If you keep it outside, consider either moving it indoors or insulating it during cold weather.

How long will it take?

Unlike a compost bin, your wormery compost can be ready in as little as a few weeks. If you choose to fill the wormery up, this will take up to a year. The majority of waste is released as liquid. This liquid feed is ready within 3 months and can be tapped off each month. It is recommended that you dilute this liquid with 10 parts water before using.

What should go into a wormery?

Like a compost bin, there are two types of waste that can be added to your wormery – ‘greens’ and ‘browns’. ‘Greens’ are quick to rot and provide essential nitrogen and moisture. ‘Browns’ are slower to rot and provide carbon and fibre. The majority should be kitchen waste such as vegetable clippings. However, worms can also digest ‘browns’ and adding approximately one third of these will prevent your compost becoming too runny and maintain a more neutral acid level, at which worms function best.

  • Food scraps such as vegetable peelings, fruit, bread and tea and coffee grounds
  • Garden refuse such as grass clippings and weeds
  • Herbivore faeces such as those of guinea pigs and rabbits
  • Rotted manure
  • Cardboard and paper such as egg boxes and newspapers
  • Fallen leaves
  • Sawdust
  • Straw
  • Twigs and bark
Other ingredients:
  • Anti-acid lime mix – adding this every couple of weeks will improve the activity of your worms as much food waste is slightly acidic
  • Egg shells – these add valuable minerals and will also reduce acidity
  • Hair
  • Natural fibres such as 100% wool or cotton
What should be avoided?

Certain foods may be too acidic for worms and may attract flies. Other foods such as fish can be eaten by the worms but may make your wormery smelly. Simply use your discretion and add cooked meats in small quantities. Compostable nappies are more suited to outdoor composting due to the compact size of a wormery.

In general do not add:
  • Meat, fish and bones
  • Citrus fruit peel, garlic and onion
  • Dairy products
  • Greasy foods
  • Weeds with seeds or pernicious weeds
  • Diseased plants
  • Disposable nappies
  • Coal and coke ash
  • Dog droppings and cat litter

How to choose your wormery

Choose the size of your wormery based on the amount of waste produced by your household and the space you have. If you have a large amount of waste and plenty of outdoor space you may want to consider a compost bin – find out more here. Wormeries are designed to allow ease of use and to prevent worms from escaping. Therefore, a well-designed wormery is a must for successful composting and recommended above a homemade attempt, especially indoors. Most wormeries will come with an instruction book that can help with any further problems. These modern designs make the vermicomposting process easy; with a wormery you’ll reap the rewards and forget about the worms themselves in no time!