A wormery is convenient way of composting kitchen waste in a container that houses a population of worms. The advantages are they can be a lot more compact, and faster to make compost than a conventional compost heap. The compost they produce is made up of worm-casts and some uneaten rotted material, it is very rich and a great way of re-invigorating soil and feeding plants. From almost the start you will also be able to harvest a liquid, known as leachate, that collects in the bottom of the bin – this is great plant food.
You can of course buy wormeries, and different designs have pros and cons, but it is also possible to build your own from a tough plastic box with a lid. This will mean its small enough for even a tiny back yard and will allow anyone to start creating their own compost from veg peelings and scraps.
To access compost you scoop off the top layer of material which contains the worms and put in another container whilst you empty out the finished compost. Before returning the worms add a layer of ‘bedding’ material such as damp torn card, or old compost. Then off you go again.
You can use a plastic box, the size of a recycling box bigger. Or start from scratch and make yourself a wooden one. You must be able to drill through it.
Metal containers are best avoided, not only are they harder to drill, but they heat up more in the sun, and that won’t be good for your worms.
There must be a lid – and it needs to be secure enough to stop your local fox knocking it off – they love to eat worms.
The finished wormery will have two compartments, one for the worms and waste material, and a sump where the run-off collects.
- A plastic container such as a medium-sized rubbish bin or a deep storage box with a lid. This needs to be opaque – worms like the dark.
- A water-butt tap – available at all hardware shops for a couple of pounds.
- A small piece of fine mesh or nylon tights
- Plastic string
- An old compost bag, or other thick plastic sheet the a 10cm bigger than your box’s base
- Gravel, enough for a layer 7.5cm deep in the bottom
- Worms! – see below.
MAKING YOUR WORMERY
- Drill a hole low down on the container for the tap, as you will need to put the box on a base to allow a collecting jar to go under the tap, the hole can go right at the bottom of the flat side. It must go onto a flat surface or you won’t get a good seal around the tap.
- To stop the tap getting bunged up use a piece of mesh or old tights as a filter, tied round the back-end of the tap with string (not natural fibre as this will rot or get eaten by the worms).
- Fill the bottom with gravel to just above the level of the tap, aprox 7-8cm deep.
- Lay the plastic sheet over the gravel and extending slightly up the sides, having first made lots of little hole in it with a sharp knife, or even a kitchen fork.
- Put the lid on and draw round it to mark how far it comes down. Just below this line drill small air holes a hand- width apart. Not too big, you want to keep bluebottles out.
- Also drill 10 small holes in the lid – you want a little rain to get in.
- That’s the structure, now it’s time to make it a comfy home for worms. Think like a worm – you want cool, moist darkness, and somewhere to burrow.
- A 10cm bedding layer should provide all those conditions and give the worms a starting home from which to venture out to feast on your old veg leavings.
- This can be a mix of leafmould and soil (to be found under a garden shrub?), compost from a heap or bought stuff or at a push torn corrugated card, moistened.
- Add worms and a starter meal of fruit and veg scraps.
It will take a while for the worms to get established, and once they do they will breed to whatever level the food supply will support. So keep feeding them, and check to see how they are doing. They will eat more in summer, but if you can insulate the box with bubble wrap in winter that will help keep them going.
Big fat earthworms are not suitable, you want the kind of red or brandling worms you find in compost heaps, and you could maybe pick out enough to get going if you have access to a pile of compost or manure. A request on RecycleinBristol may also get results, I have crossed town with a takeaway box to get some worms and have then passed on some to other people. Once your worms are happy they breed fast so you can share.
Or you can do a search and buy worms, but apart from the expense I think it is good to avoid having anything living sent in the post.