In this blog we are looking at wormeries. Our Horticultural Technician, Meg Evans, explains what a wormery is, its benefits to your garden, what worms to use and how to feed them.
What is a wormery?
Wormeries are closed systems in which organic matter is broken down into nutrient rich compost and liquid feed via worms. You may hear wormeries referred to as vermiculture or vermicomposting – ‘vermis’ being the Latin word for worms! Isn’t Latin great?
How can a wormery benefit my garden?
Wormeries can be a fantastic source of nutrient rich material to improve your soil quality, feed plants and do something more productive with your kitchen scraps.
Worms digest the difficult lumpy bits in soil and excrete worm castings, which are a fantastic aid for structure and nutrients. Worm castings are sometimes referred to as multivitamins for plants, because they have such a rich nutritional content. They’re also rich in microbial life, essential for keeping your plants and soil happy and healthy. They can be in fact so nutrient-packed it’s worth noting you should moderate your use to avoid damaging plant root systems. Generally, it’s recommended that you add 10-15% worm castings by volume into your garden soil.
Liquid fertiliser, or worm tea, will either collect in the bottom container of a multi-tiered system, or soak into the worm castings in a single tiered system. A multi-tiered system if managed properly will not produce a lot of liquid (and if a lot of liquid is being produced, especially if its smelly, this is a sign the system is too wet and has become anaerobic, which we don’t want to feed to plants). If this happens add some shredded paper and/or cardboard to mop up some of the excess liquid. This will be covered in more depth in a future blog focusing on troubleshooting a wormery.
To harvest tea from the castings, fill a porous bag (such as an old t-shirt or cheesecloth) with the worm compost, making sure not to include any worms!
Fill a bucket or container with rainwater or distilled water, tie up your worm castings bag and let the bag steep overnight. The water should turn a light to dark brown, which is your brewed tea. Separate the tea from the castings and dilute at a 1:3 or 1:2 ratio of tea to water, depending on how strong you’d like it. It’s useful when starting out to add the minimum amount recommended and see how your plants do – you can then proceed to adjust for best performance. Use your liquid fertiliser within a few days for maximum freshness, and don’t forget to mix the castings into your soil.
What do you need to make a wormery?
Bedding for the worms:
Typically, coir is used but you can also use moist, shredded card and paper.
The wormery itself:
Although you can buy pre-made wormeries, they can come at a bit of a cost. If you’d like to make your own, all you need is three containers, the top two with breathing holes. With the help of some bricks to weigh down the containers on top, the bottom container will collect the liquid feed and you’ll be left with the compost on the top and/or middle layer. Single tiered containers can also work, but they’re higher maintenance as you’ll need to pay close attention to how much waste your worms are consuming and change out the good stuff often.
You’ll also of course need the worms themselves, and they’re not the worms you’d find in your garden. Although earthworms are brilliant creatures, they’re not adjusted to living in pure decaying organic matter. That’s why we use specific worms for wormeries, known as tiger worms and red worms. Here’s a list of suitable worms which can be used:
Eisenia foetida (tiger worms, sometimes known as the brandling worm)
E. andreii (a close relative to tiger worms)
Dendrabaena veneta
You can order these worms online or visit your local fishing shop, as they’re often sold as bait.
What can you feed your worms?
Everything should be fed in moderation, just like with we humans!
Include food scraps such as:
Fruit and vegetables (raw or cooked)
Crushed, cooked egg shells
Shredded wetted paper and/or cardboard
Human and pet hair (not dyed or chemically bleached!)
Flowers
Small amounts of green garden waste
Coffee grounds
Loose leaf tea
Don’t include:
Woody material – this slows the system down and can cause issues
Avoid adding or add in small quantities infrequently:
Meat and fish
Dairy
Citrus fruits (unless cooked)
Onions
It’s important to remember that wormeries take time to establish. When you set up a wormery, add a layer of food for them on the top layer, and leave for a little while to get an idea of how much they’re eating so you don’t overwhelm them. But most importantly, enjoy your new worm friends!