Making your own compost is the ultimate in closed-loop recycling – and the best bit is it’s a natural and free process.

Compost worms or brandling worms do a fantastic job breaking down kitchen scraps and plant materials into nutritious compost (alongside microorganisms, insects and fungi). In a wormery this is called ‘vermicompost’ – which sounds very posh, but it’s actually created from worm casts or worm poop!

This kind of compost is very nutrient rich and can be used as a soil conditioner, plant feed, top dresser and as part of a potting mix.

But a full size wormery can be expensive and if you have a small garden or balcony, it can be out of the question. Time for a DIY alternative.

What you’ll need:

• 3 shallow plastic stacking trays in a dark colour, approximately 28cm x 40cm and 13cm deep
• 1 close-fitting lid to fit onto the top tray
• Drill with 5-8mm drill bit
• Fine sandpaper

How to assemble:

1. Drill holes every 3cm into the base of two trays – and add holes to the sides to improve aeration.
2. Sandpaper around the holes to ensure there are no sharp edges.
3. Stack up the trays, one inside the other, popping the one with no holes at the bottom.
4. Put 4 large stones in the bottom and middle tray to create a bit of space between the layers.

Add your worms – and their food

Once your wormery is ready, it’s time to add the worms. If you already have a compost heap you can add some worms from here – but you can also buy brandling, red or tiger worms from a wormery specialist or fishing shop. These worms are different to earthworms that live in the soil, and which are unsuitable for worm composting.

Add a few scoops of damp soil, compost or shredded paper to the top section along with your worms. Cover the top tray with five sheets of double newspaper. This helps to get the worms accustomed to their new home and prevents them leaving. Eventually you can add your lid.

Over the next few weeks, gradually add your kitchen waste – this can include chopped-up vegetable peelings, crushed eggshells, coffee grounds and tea bags. Don’t add too much too quickly, and don’t add bones, meat, fish or dairy. Citrus fruit needs to be kept to a minimum. They also eat much less over the winter so reduce the feeding to less than half over that period.

Pop your wormery somewhere sheltered between 12-25 degrees and out of full sun. In the winter you might want to bring it into the protection of a shed or greenhouse.

What happens next?

The worms do not eat the food waste directly, instead the food is broken down by microorganisms, bacteria and fungi – and the worms eat the decomposed organic material.

Be patient! After eight to 12 weeks, you should see lovely, crumbly worm compost collecting in the middle tray. The bottom layer will also be collecting nutrient-rich liquid – which can also be used as a plant fertiliser when diluted. Double the nutrition, for very little extra effort.

For more organic gardening tips and projects, head to www.gardenorganic.org.uk, where you can also find out how to support the charity by becoming a member.