Composting with worms (sometimes called vermicomposting) is a method of composting kitchen waste and small amounts of garden waste.
The worms which are different to garden worms, eat their way through the materials in your worm bin and produce a finely textured, rich compost.
You can buy worm bins from specialist shops or make your own. Some worm bins come with worms, but sometimes you have to buy them separately. To find out more about where to buy worm bins and worms or how to make a worm bin please follow the links below:
Master Composter
Wiggly Wigglers
HDRA
What to digest
YES
You can put the following materials in your worm bin:
Bread
Cardboard
Egg Shells
Fruit
Left over food (such as pasta, beans and pizza)
Small amounts of grass
Tea bags/leaves & coffee grounds
Vegetable scraps
NO
The following materials should not be put in your worm bin:
Garden waste
Large amounts of citrus fruit and peel –worms do not like acidic environments
Meat, fish and dairy products
WHERE
When thinking about where to put your worm bin you have to consider the worms needs as well as your own.
Temperature
Worms need the right temperature to live. They prefer a constant temperature and should be kept between 12 – 25 oC (50-77 oF). Both too low and too high temperatures can kill worms.
Keep your worm bin out of direct sunlight to prevent the bin overheating.
While you might consider keeping your worm bin outside during the summer, worms will not be able to survive outside during Scottish winters. If you keep your worm bin outside you will have to move it to a warmer spot over the winter (porch, garden shed etc.) to prevent your worms from freezing to death.
Access to the bin You should put your worm bin in an easily accessible area. This can include garden shed, porch, even your kitchen or spare room.
HOW
Getting started
You will need to spend a bit of time setting up your worm bin. Shop-bought worm bins usually come with all that you need, including worms and detailed instructions on how to set up the bin.
To set up your worm bin you will need:
1. Composting worms
The worms that you need for composting are different from the worms that you find in your garden. The most common varieties used are brandling and tiger worms. These can be mail ordered from a number of organisations, including Wiggly Wigglers and HDRA.
The amount of worms you will need depends on how much food waste you want to compost. Worms can eat about half of their weight of food every day.
Worms reproduce quite quickly so it may be best to start with a small amount of worms and increase the amount of food waste you add to the bin as the number of worms in your bin increases.
2. Bedding material Worm bedding holds moisture and provides a medium for the worms to work in. There are a number of materials that you can use as bedding:
Shredded paper or cardboard
Mature compost
Leaf mould
Coir (coconut fibre)
3. Food waste Once you have your worms, bedding and food waste the first step is to add the bedding to your bin. It may be best to add a layer of gravel first to improve drainage. You should add a 15cm (6 inch) layer of moist bedding to your bin and then add your worms.
Once they have moved into the bedding you can add some food waste and cover it with a layer of moist newspaper. Leave the worms to settle in for up to three weeks.
When the worms start eating the food waste you can start adding more.
Adding food
The amount of food waste that you can add will depend on how many worms you have. It is best to add food materials in layers (not more than 5cm – 2 inches deep) and cover the food with a layer of moist newspaper. Chopping your food waste into small pieces will help the worms to process it.
Emptying your worm bin
You will need to empty your worm bin when it is full - either of finished compost or of food waste. The finished compost is dark in colour and crumbly.
If you have added your food waste in layers, the ready compost will be on the bottom of your worm bin.
The easiest way to harvest the finished compost is to remove the top layer with the freshest food waste and the layer immediately underneath – these should have most of the worms. Remove the finished compost underneath and return the worms and uneaten food waste with some new bedding material to the worm bin.
For further details on composting with worms and information on where to buy worm bins please visit Sort It.
