The Gardeners Almanac

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My Back Garden

Wormery


Overview:

Purpose made Wormery

Many gardeners already use Compost heaps / bins to rot down their organic waste, however, a less common sight in the garden is a wormery, which does a similar thing.

All you need is a suitable container to keep your worms in.

This can either be a purpose made, or one you have made yourself from an old plastic dustbin.

Purpose made bins may have a tap to drain off the liquid manure, a bib tap would do the same for a home made bin.

In fact while you are at it, why not make two bins, this will allow you to continuously produce worm compost, i.e. when your compost is ready in one container, you simply remove the top layer of compost and use this to start the second batch.


Method:

Firstly,place a 75mm (3”) layer of cobblestones in the bottom of the bin (they are easier to clean) then cover the stones with a perforated board, marine ply is ideal.

This allows any liquid produced during the composting process to collect here, this can later be poured out, or drained off by the tap mentioned above.

Next, place a 75mm (3”) layer of well rotted compost and / or leaf mould on top of the board.

This is where your worms will live and should be kept moist at all times.


Worm Types:

Clump of pink coloured worms

dendrobaena

A view of a 'Tiger' worm complete with its stripes

Brandling Worm

Earthworms are not really suited to this environment so it is much better to purchase from a specialist supplier, or failing that you may be able to purchase some from your local fishing tackle / bait shop.


What you want is Brandling worms also known as Tiger worms (eisenia foetida)

Alternatively go for dendrobaena, this is a bigger, more acid tolerant worm which can digest 30 % more material.


Add the worms to the compost layer, the number required will be dependant upon the speed you want the compost and how much feeding material is available.

50-100 worms should be sufficient to start off with, if you find you want the process speeding up, add more worms!

The worms reach maturity in about 10 weeks.

Cover the worms and manure layer with 25mm (1”) of dry soil, not peat!


Next place about a 75mm (3”) layer of kitchen waste on top of the soil and cover this with another 25mm (1”) layer of dry soil.

Finally cut a piece of old carpet to the shape of the bin and place on top of the soil, this will help retain moisture, provide darkness, thus enabling the worms to work near to the surface.

They will continue to breed provided they have enough food, and are kept at the right temperature and do not become too overcrowded.


Aftercare:

Add small amounts / layers of kitchen waste at regular intervals.

Worms eat mostly organic kitchen waste!

For example: Bread, Cereals, Fruit and Vegetable waste.

Avoid Garlic and Potato peelings, and anything containing saturated fat or vinegar.

Break all the waste into small pieces before placing it in the wormery.

Add the waste little and often rather than large quantities of food at once, as this can cause overheating and this can kill the worms.


Don't worry about feeding them when you go away on holiday, they will thrive without food whilst you are away, providing they are not disturbed.


Composting can be carried out all year round, however,worm activity ceases below 5ºC (40ºF) therefore you need somewhere to keep your container of worms during the winter months.

Aim for temperatures above 8ºC (45ºF), the use of insulation such as old carpets or an old cylinder jacket will help.


When the bin is nearly full, empty out the soil like compost and prepare for the next batch.

Remove the layer containing the worms and place it in the next bin, then continue as before.

It is usually possible to harvest worm compost from your bin about every 4-9 months.


Liquid Manure:

Collect or pour out the liquid that has been produced in the bottom of the bin, mix it with clean water at a ratio of 10:1 and use the mixture as liquid manure.

The compost can be placed on the garden as mulch or mixed with a base fertiliser and be used as potting compost.