What to compost
Worms enjoy a varied diet eating any decaying organic matter. You can put in;
- Any raw vegetables, except for onions, shallots, leeks and garlic that are best used in small amounts or cooked first
- Any cooked vegetables
- All fruit, except citrus peel, which needs to be limited or preferably cooked before adding
- Tea bags, eggshells, coffee grounds and small amounts of bread
- Limited amounts of newspaper, shredded office paper and cardboard, but not glossy magazines
- Small amounts of garden waste such as annual weeds, leaves and other soft green material
Remember: Fruit and vegetable scraps that contain seeds can be included but the seeds may germinate in the wormery.
What to avoid:
- Dairy products, fat, grease, meat, fish and bones as these are likely to attract unwanted pests and flies
- Larger quantities of tough leaves and woodier material as it will slow the system down
If there is a lot of garden waste, which could overload the wormery, it is often best to have an ordinary compost heap as well.
Organic waste usually has a high moisture content. If the lid is kept on, dry conditions are unlikely to occur. Add water only if the wormery appears dry.
An established wormery can be left without the addition of food for up to four weeks. However, the liquid may accumulate which needs to be drained off to avoid waterlogging.
Occasionally fork the compost over gently with a hand fork to check that the worms are present and healthy.
Ways to increase the rate of composting:
- Aim to provide and maintain the desired temperature especially during the winter months
- Add extra worms (see below for suppliers) to the existing population
- Avoid overloading the wormery with waste
- Wormeries with a greater surface area will also work faster
- Using worm compost and liquid
Emptying the wormery:
Wormeries are usually emptied when they are full; this takes about 8 to 12 months. You must separate the worms before using the compost.
The worms tend to congregate in the area just below the top layer of food waste. Simply remove the top 20cm (8in) layer and use it to restart the wormery again.
Alternatively, if the weather is warm and dry, spread the contents of the wormery thinly over a polythene sheet. Cover the centre of the compost with layer of wet newspaper. As the compost dries, the worms will move towards the cool, moist compost under the newspaper from where they can be collected. Once emptied, and the worms separated, the wormery can be filled with a new layer of bedding, the worms returned.
Many wormeries use stacking trays for the worms to work up through. The finished compost is in the bottom tray and can be removed. The tray is then emptied and returned to the top of the stack. This makes sorting the worms unnecessary.
Worm compost and liquid – how to use:
The worm compost can be used as a general soil conditioner or as a constituent of homemade growing media. It is generally rich in nitrogen and potassium.
The liquid drained from wormeries can be used as a liquid fertilizer on garden plants after diluting with water at a rate of 1 part liquid to 10 parts water. Its nutrient composition will vary.