Worms and Wormeries

How to compost

Compost Safely

Your compost ingredients

Emptying your Bin

To turn or not to turn?

How long to compost?

Worms and Wormeries

Topical Composting

Kitchen Waste

Prickly prunings

Weeds and Weeds

Too much grass?

Leaves for leafmould

Seasonal Tips


Advice sheets
Unwelcome Guests

Worms in the Compost Bin
There are 2 stages in the composting process a hot fast one and a slow cool one. At the top of the bin, the material rots down at a high temperature and sinks quickly. Beneath this, compost that could be used for mulching slowly turns into fine, crumbly material. It is here that worms play a vital part.
Worms naturally live in the soil and break down plant debris so will be attracted to a compost bin where there is a lot of plant debris. When a bin sits on the soil, it will quickly fill with worms. You do not need to add any more worms.
You may find them round the lid of the bin where there is a lot of condensation and it is moist. This is quite common and does not mean there is anything wrong.

Special Worm Composting.
Worms will turn peelings and kitchen waste into deluxe compost, so rich it is more of a fertiliser and invaluable for container grown plants. Here's how to convert your kitchen scraps into this best of composts.

The Worms we use:

There are at least 25 different species of earth worms in Scotland. They break down decaying vegetation like leaves and plant debris and this adds valuable nutrients to the soil. Many will provide good drainage by burrowing down 20-25cm into the soil and a few go even deeper. Some species live mainly on the surface in leaf litter and decaying vegetation and it is these that we use in our wormeries. These are also the species you are most likely to find in your Compostabin, it is an ideal habitat for them.
The species most commonly used for a wormery are Eisenia foetida (the brandling or tiger worm), recognisable by its red stripe, and the larger Dendrobaena venata (the European night crawler).

A Worm's Life
Worms are hermaphrodite, having both male and female reproductive organs. Each worm produces egg capsules, but must first be fertilised by contact with another worm. Each healthy worm, under favourable conditions, will produce an egg capsule every 7 to 10 days. Between 2 and 24, usually 4, baby worms will hatch out in 2 or 3 weeks. The new worms will reach breeding age in 2 or 3 months. The compost worm will then reach its full size after another 3 or 4 months.

Ideal Living Conditions
worm paperWorms need a damp, but not soggy, environment. They thrive in cool conditions: the optimum temperature is 15C, though some species, notably Dendrobaena, can survive in temperatures ranging from 3C to 27C. However, survival is not the same as being content - worms become dormant at the extremes of their temperature range and stop feeding. So to keep them eating lots of your compostibles you need to give them their preferred temperature range - 10C to 20C - so site your wormery in a shady place and protect it from winter frosts.
A thick layer of damp newspaper helps to insulate them from temperature swings.

worm foodWorms need a steady supply of fruit and vegetable peelings. They will eat most types of fruit and vegetable waste, but not orange, lemon or grapefruit skins (these are too acid) and they dislike onion skins and leek leaves. They are particularly fond of banana skins and melon rind.
Worms feed on decomposing material, so do not expect them to get stuck in to the fresh stuff you put in. Having no teeth, gums or tongue!, they have to suck tiny scraps from the soft edges of their food. If you cut up the material you put in there will be more edges to soften more quickly which will allow the worms to start eating sooner.
Worms like to eat newspaper and cardboard (the glue between the layers of cardboard is good protein for them), so the thick layer of damp paper or card that goes on top of their food will be eaten away and will need replacing.
To aid their digestion worms need egg shells. Worms break up the food they eat in their gizzard, just like a hen, so require tiny bits of grit to act as grinding stones. Adding crushed egg shells to their food provides them with grit and the calcium in the egg shells help to prevent their environment becoming too acidic.

Worms need air so make sure the bin isn't waterlogged. Worms can drown.

the wormery
There are several types of wormery available, usually costing around 65+. You can also make your own wormery very cheaply. Choose a shady part of the garden, make a square wooden box, 45cm x 45cm x 60cm tall. Staple a permeable membrane to the bottom of the box to allow excess liquid to drain out and stop moles burrowing in. Make a solid, well-fitting lid for insulation and to stop your worms being soaked by the rain or eaten by blackbirds.
worm beddingFor a commercial or home-made bin, worms will need bedding. Place a layer of damp leafmould, 5cm deep, or soak a coir brick and use it as their base. Place approximately 1kg of works on the leafmould or coir and scatter a thin layer of food on top. Place a thick layer of damp newspaper over the food and leave the worms to it.
After about a week add a small bucket of chopped up kitchen scraps. As the worm population increases, you can add more scraps. Make sure there's always a good thick layer of damp paper to keep your wormery moist and cool. You'll need to keep adding more paper as the worms consume it.
There is usually a sump at the bottom of commercial wormeries to collect liquid. Be sure to drain this off from time to time. You can dilute this 1 part liquid to 5 parts water and use it as a feed for container grown plants, or simply pour it on a compost heap.

Harvesting the wormcast
After a year there should be a good thick layer of worm-made compost at the bottom. On a sunny spring day, place a sheet of cardboard close to the bin and, using gloves, scoop out the top layer of semi-decomposed material and put it on the card. Then pile up the finished compost from the bottom of the wormery on another sheet of cardboard. The worms will escape from the light so, after about 10 minutes, you can skim off the top layer of compost knowing there will be no worms in it. Repeat this process till you've separated most of the compost from its inhabitants.
Leave your worms a 2-3cm layer of finished compost for their "bed", put the worms back on top of this and cover them with their food and an extra thick layer of damp newspaper or soaked cardboard.

A wonderful addition to potting mixes. See DIY Potting Mixes. As wormcast is much stronger than general compost, use half the quantity recommended in the recipes covered in that page. An added advantage is that wormcast contains no weed seeds.
Wormcast can be used as a mulch but this material is very precious so target it with care. Container grown plants often need a pick-me-up in early to mid-summer, so sprinkle some wormcast on the surface of the pot and watch your plants respond.
Tomatoes are particularly appreciative of wormcast.

Any problems with your wormery Contact us