How to make your own wormery

A wormery will recycle your waste food to make a superb fertiliser for your crops and a living soil in your containers. Wormeries are perfect for small spaces: they’re small, don”t smell and make compost faster than conventional composters. You can either buy one (in the UK many councils offer them at discounted prices) or it can be fun and rewarding to make your own.

It’s easy to make your own! 

When I started growing I imagined that wormeries were complicated and hard to make. The truth is that they are simple and easy. 

Worms will be happy in any home that meets their basic needs: air, darkness, and moisture. It also shouldn’t get too hot or cold.  There are several ways to make a wormery. The easiest is to use an old plastic (or wood) box. Here’s how to do it (I’ll share other ways in the future). 

What you need

To make a simple box wormery you’ll need a shady space (under a bench or table is fine) for it to live and:

  1. A large plastic box with a lid (see below)
  2. A drill
  3. 2 bricks or pieces of wood to stand it on.
  4. Some newspaper or cardboard. 
  5. Worms and worm bedding

How to make it

1. Find a large plastic box, with a lid (you can improvise a lid if it doesn’t have one)If you can find a box that is UV treated it will last longer outside (most plastics designed for outside use eg recycling boxes will be OK). There is not really a minimum size – but the larger the surface area of your box, the more food waste you’ll be able to feed it. Anything much smaller than 14 inches (35cm) in diameter will be quite limited.

 

 

An old recycling box like this is perfect. These normally come with a lid but it's been lost so I will have to improvise. This one is a good size - 50cm x 35cm - but a bit smaller would also be OK.

An old recycling box like this is perfect. These normally come with a lid but it’s been lost so I will have to improvise. This one is a good size – 50cm x 35cm – but a bit smaller would also be OK.

 

2. Drill holes in the base of the box. Worms need air to breathe (just like us) – so drill enough holes to ensure a good air flow. I used a 1/2 inch (12mm)  drill piece here – but any reasonable sized holes will do. (Just bear in mind that smaller holes are more likely to get blocked).

You want as much air as possible to get in. So the more holes you can drill - while keeping the integrity of the box intact - the better.

You want as much air as possible to get in. So the more holes you can drill – while keeping the integrity of the box intact – the better.

3. Put the box on bricks (or anything else that will do as ‘feet’) to ensure air can flow up in through the holes.

Standing it on bricks lets the air get to the air holes. No bricks? you can stand it on anything else you can find - like bits of wood.

Standing it on bricks lets the air get to the air holes. No bricks? you can stand it on anything else you can find – like bits of wood.

4. Cover the bottom with a sheet of newspaper. This will help ensure the worms don’t fall out! You don’t need to build Fort Knox – the worms will only try to escape if they’re unhappy – for example if it gets too acid inside (this can happen if too much onion or citrus is added).

A layer of newspaper over the holes will prevent the worms falling out when you first put them in. You can put a drainage layer under this if you like - using eg stones or twigs - but this is not necessary. It can improve aeration, but it also has to be seperated from the worm compost when you harvest it which can be a bit of a hassle.

A layer of newspaper over the holes will prevent the worms falling out when you first put them in. You can put a drainage layer under this if you like – using eg stones or twigs – but this is not essential. It  will improve the aeration, but it also has to be seperated from the worm compost when you harvest it which can be a bit of a hassle.

5. Drill small air holes in the lid and the side at the top. If you’ve got a sheltered place to put your wormery, you can drill plenty of holes in the lid to let air in. But if your wormery will be exposed to the rain, just drill a few – otherwise the box will get water logged in wet weather. You can add more holes to the top sides of the box instead. However you do it, the worms need a good supply of air – without letting in excessive amounts of light (worms need darkness).

 

Drill a line of small air holes in the top sides of the box. You can also put holes in the lid - but not too many if the box will be exposed to the rain a lot.

Drill a line of small air holes in the top sides of the box. You can also put holes in the lid – but not too many if the box will be exposed to the rain a lot.

 

6. Add about half a bucket of worm bedding - enough to cover about an inch in the bottom of your box. The bedding is what your worms will live in when you first put them into the box. You can use worm compost, home made compost, shop bought compost, or coir (coconut fibres) as bedding. The bedding is important to help your worms ‘settle in’ to their new home. They’ll feel happiest in worm compost. That’s because it contains all the microbes that they need. If you’re lucky enough to have a friend with a wormery (see below) ask for some worm compost to use as bedding.  Whatever bedding you use, make sure it is damp, like a rung out flannel.

This is partly decomposed worm compost from another wormery. It makes good bedding for worms. But worm compost is not essential - there are other alternatives.

This is partly decomposed worm compost from another wormery. It makes good bedding for worms. But worm compost is not essential – there are other alternatives.

  7. Add some worms: You can get the right sort of worms on line, from a fishing tackle shop, or a compost heap. Even better, from someone you know with a wormery. An established, healthy wormery will contain several thousand worms. Collect 300 – 500 of these, or as many as you can. The more you start with, the faster your wormery will become productive (worms double their population about once every three months – so your friends wormery will return to full power again in just a few weeks). NB: earthworms – the worms you dig up in garden soil – are not suitable for wormeries.

 

A common name for the worms you use in wormeries is Tiger worms. Various varieties are suitable. You only need one variety, but if you have more than one your wormery can be more efficient. Two common species used are: Dendrobaena venata and Eisenia fetida

A common name for the worms you use in wormeries is Tiger worms. Various varieties are suitable. You only need one variety, but if you have more than one your wormery can be more efficient. Two common species used are: Dendrobaena venata and Eisenia fetida

 

8. Add a small supply of food: tea bags, banana skins, vegetable peelings, coffee grounds, are all good. If you chop it up, the worms will be able to process it faster (don’t liquidise though). You can also add processed and cooked food to a wormery – but avoid adding in any quantity, particularly until your wormery is well established. Also avoid adding onion skins, citrus, very spicey or oily foods. As well as food waste, you need to add about 20 – 30% carbon rich matter – carboard, newspaper or wood chip.

Vegetable peel, banana skins, pea pods, tea and coffee grounds, a bit of pasta - all good food for worms.

Vegetable peel, banana skins, pea pods, tea and coffee grounds, a bit of pasta – all good food for worms.

9. Cover the surface of the worms. Any old cardboard, newspaper or an old towel will do. This helps keep the light out and the moisture in.

 

Here cardboard is being used as a cover - but an old T shirt, towel, or simply some newspaper will do the job just as well. I sometimes give it a quick watering to keep it damp.

Here cardboard is being used as a cover – but an old T shirt, towel, or simply some newspaper will do the job just as well. I sometimes give it a quick watering to keep it damp.

 

 

10. Add the lid. I’d lost the lid for this box, so I’m improvising with an estate agents sign I found discarded in the road. I’ve sandwhiched two pieces of board together with a gap between them. I drilled holes in the bottom piece so that air can get in, but not in the top to keep it waterproof – at least that is the theory!

This lid is improvised from an estate agent sign. It's functional rather than beautiful - and I will be tucking this one out of sight under a small table!

This lid is improvised from an estate agent sign. It’s functional rather than beautiful – and I will be tucking this one out of sight under a small table!

That’s it. All you need to do now is place it in a shady, sheltered spot out of direct sunlight. Feed it a little and often to begin with. Take care not to add too much food at one time or it will become smelly and unattractive to the worms (it putrefies). I plan to write more on caring for wormeries in the future – in the meantime, here’s a piece, In love with worms, that I wrote a while ago with some ideas on what to feed them. 

 

Making your wormery look attractive

I’d be the first to agree that this is not the most beautiful model! So you might want to tuck it out of the way eg under a table. Alternatively you could decorate the plastic box or put plant pots on the top. If you want a more attractive wormery, I’d recommend buying or making one from wood. Wooden wormeries can also double up as benches –  and make ideal seating for small spaces. Wood is also a better insulator than plastic and it breathes better, too.  But a plastic box will work fine and is so easy to make, that’s why I chose to describe here.

 

Here’s a video of how you can do it!

 

48 comments… add one

  • Great project but it looks like you are losing a great nutrient resource from your wormery because the liquid is draining out of the bottom of the box drainage holes. I suggest you should have another old recycling box with no holes in the bottom, with a brick or something to keep the active worm box clear of the bottom of the liquid catchment box. Otherwise you are losing all the valuable worm-pee!

    Reply
  • Hi.
    Could you not use multiple recycling boxes with holes, and stack them when full. So the worms migrate upwards like they do in (very expensive) tray wormeries? Might give it a go…
    Brian

    Reply
    • Yes, Brian, you certainly can – it’s a great idea. I’ve not done it myself by I know others have. Definitely worth a go.

      Reply
  • I am in Turkey and brought worms back with me from the uk. I have them in a bucket at the moment and want to move them into something where I can separate the compost. Will this disturb them? Also I want to add some manure type compost that has a lot of worms to them, is it ok to do this?
    Thank you

    Reply
  • I know the book to help you wormers get started. Its a mind of information and is available on Amazon….. Composting with worms. Why waste your waste. Written in the UK for UK wormeries!

    Reply
  • This has really inspired me to have a go at building a wormery for my allotment.
    Is now a good time to start a wormery or does it not matter?
    Should I move the wormery into the polytunnel in the winter?
    aman

    Reply
  • How do you take the compost away without taking away half the worms or disturbing them? I’d love to make one!!!!
    Thanks
    Kaz

    Reply
    • Hi, you can’t avoid disturbing them a bit, but they quickly settle back in. Just take out the top half or so (this is where the majority of worms will be) and put it in a bowl or bag while you harvest the compost at the bottom. Alternatively you can put a divide across the middle of the box and drill holes in it (for the worms to crawl through) – then fill one side of the box and then the other. The worms should migrate from the side with the finished compost into the the newer material.

      Reply
  • I teach preschool and would like to use a clear container to make something for kids to watch worms in my classroom. Is there a reason that wormeries are plastic instead of glass?

    Reply
    • Great idea! Worms don’t like light which is why you don’t see glass ones around much. But check out george pulling ton and nurturing nature – he makes them with a glass panel so kids can see in. The panel is covered when not being viewed I think.

      Reply
  • i contacted out local organic compost wormery and they mentioned that protein was important for them and calcium so they use cereals and beans for protein and eggshell waste for calcium. just thought id mention that for any vegetarian wormers that they can add the dust at the end of cereal packets as a good source of cereals for them to get their protein:) I’m just making a new wormery now have made one for the doug poop in my yard not sure what i will do with it but now making a vegetable one for my veggies. you can also feed them your run of the mill peat compost that you buy in a store and once it has been digested by the worms it is considered organic! so long as there is no gmo!

    Reply
  • Mark, Great informative site. I built a worm bin 4′x8′ with the idea to catch the leachate to spray on fields and make tea from the worm castings. I feed them paper shreds from work and discarded vegetables from the local grocery store. Means, good and bad, includes onions, citrus, garlic etc. I pre-rot the vegetables in a barrel and add in layers with the shavings. They have been eating about a 30 gallon bag of shavings every two weeks. I have been collecting the leachate, about 10 gallons per month.

    Now i read in several sites that the leachate is not a good product rather it is anaerobic and should be discarded. What is your opinion of leachate?

    Worm castings – the worms are vigorously working the top of the bin but i may have loaded it too fast. Now a foot deep, the lowest section(4-6″) smells similar to good dirt, but there is a middle section that is not fully broken down and not many worms. Too wet, too much food, wrong kind of food?

    Thanks

    Reply
    • Hi Mark, i read the same thing about leachate (for others reading this, leachate is another name for the liquid sometimes called worm tea that runs off wormeries) so my wormeries are not designed to collect it. On the other hand, some experienced gardeners I know swear by it – so its one of these things thats hard to fathom – is it good or not. I wish I knew the answer! If you discover more info, I’d love to hear.
      In answer to your other questions, you are operating on a much larger scale than I have experience of and this tends to throw up a different range of issues. I’d recommend trying to get in touch with vermicomposters working on a commercial scale or perhaps look up this site: http://vermicomposters.com/

      Reply
  • Hi, very nice and usefull blog I found today after reading your article in Permaculture Magazine :-)
    A couple of questions: do you use vermicompost straight after harvesting or it need a minimum time to “rest”? Probably sometime it need to be stocked longer, is there a maximum time it can “rest”?

    Thanks!

    Reply
    • Hi Pierre
      Really glad to hear you’re finding some useful stuff here. Worm compost is ready to use as soon as its harvested (sometimes it benefits from a sieve first). Probably the sooner the better – one of the great things about worm compost is all the microbial life that lives in it – this will be high when the compost is fresh but will slowly diminish over time. It does however keep fine for a while – I keep it in a plastic bucket with an ill fitting lid so that air can still get in so that the worms in can continue to live. I’ve kept it fine for two or three months. It may well keep even longer, but three months or so is the longest I’ve kept it for.
      Happy worm farming!
      Mark

      Reply
  • Thanks Mark, great guidance. I’m going to get onto this, just need to source where I can get my worms from.

    Reply
  • I would like to start a wormery for but I want to use them for fishing. Would I use that same procedure.

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    • Hi Charlie, the same procedure should work fine. If you want big, fat healthy worms then adding a bit off well rotted horse manure every now and again will help with this. (But is not essential).

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  • Hi!, my question is, how do you prepare your wormery for winter? I live in Québec and here, winters are very cold! You got ideas?

    P.S. I very love your website!

    Reply
    • Hi Michael
      There’s a few things you can do
      1. Make sure the wormery is nearly full (ie don’t empty the worm casts just before it gets cold). The more volume you have, the less likely it will be to freeze – the worms will all congregate in the centre.
      2. Place the wormery out of the way of strong winds and put it the warmest spot you can find – somewhere inside is ideal but most of us don’t have space for that.
      3. You can try and add extra insulation to the wormery eg wrap it in a blanket or in bubble wrap (I’ve never found this necessary but I don’t think our winters are as cold as yours).
      4. Take care not to overfeed the worms during the cold months – the food will go rancid – although keep an eye on them and feed as necessary, as they will consume some stuff on warmer winter days.

      Hope this helps?

      Mark

      Reply
  • Hi Mark,
    Re the toilet paper answer and carnivorous animal faeces, there are several wormeries designed just for composting dog/cat waste. They use tiger worms like you mentioned somewhere. Very expensive, £50 to hundreds – but those are big ones for public areas. What they say is that they’re dedicated wormeries, pet waste only – no other scraps as the pathogens can multiply in that and worms may not be able to cope – and the composted material/liquid should only be used on ornamental plants, not any for human consumption (so not in beds growing both either). Apparently worms are bred using manure. http://www.dogpoodisposal.org.uk/dog-waste-decomposer.html (charming little logo! hmmm); http://www.earth-essentials.co.uk/products.htm; http://www.wormery.co.uk/dog-poo-wormery.htm.
    So, make your own like Mark’s above, or instructables.com for different designs such as multilayer or built-in liquid collection!

    Reply
  • the shells of shrimp are suitable for worms ..?

    Reply
    • Great question. Honest answer? I’m not sure.. But my guess is that they’ll be fine and could add valuable trace elements. I’d add in small quantities at first and observe what happens to them – do the worms eat them? If you wanted to add in larger quantities (eg if you’re working in a sea food restaurant) I’d recommend contacting a professional worm farmer to get a more authoritative answer in the first instance.

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  • can i use the toilet paper in the wormery how 20 – 30% carbon rich matter?

    Reply
    • card toilet rolls are fine, used paper (which I guess you’re referring, too?) I’m not sure about. The general rule is that faeces from vegetarian animals (eg rabbits, hamsters) are OK in small quantities but faeces from carnivorous animals (cats, dogs) are not. To be on the safe side, I’d avoid using it until you can find a reliable source to tell you if its OK or not.

      Reply
      • On a similar vein, I’m a science teacher and have giant African land-snails at school. Sadly I accidentally ‘killed’ all my snails recently and am sure it was through putting hand-towel on their peat, in order to try to dry it out; I then remembered reading that for hamster bedding you can use kitchen towel but NOT toilet paper or paper hankies as they contain bleach. So the poor snails were probably bleached to death. The same thing I am sure would happen to worms (they didn’t turn white; they were poisoned). On a different note I am a very keen gardener and use the liquid on my best plants – eg roses and clematis in spring, then any favourite plants through the summer. Half a litre of liquid to a 5 litre watering can of water. It is really good and the plants grow quickly and strongly. We use this more than the compost; it is like liquid gold.

        Reply
  • Hi Mark,
    Hello from sunny Sydney Australia. Just love your website and your videos. You are fantastic in the way that you help anyone grow vegies without a garden and your ideas are absolutely great. You mentioned that the compost worms from my worm farm can live in the soil in the pots my vegies are growing in. Is this correct?

    Reply
    • Hi Anney
      Nice to hear from you in Sydney!
      Yes, in my experience, worms seem to live quite happily in pots. The bigger the pot, the happier the worms will be – I wouldn’t put them in small pots (anything much less than 30cm diameter). Also make sure the compost is kept moist as the worms will die if it gets very dry. I’m not quite sure how long worms can live in a pot, but I know it is at least a year as I’ve found them quite happy in a pot after this length of time.
      Hope this helps.
      Mark

      Reply
  • Hi! Thanks so much for this information! I have just finished making my own wormery using a plastic bin. I’m not sure if I can post a photo on here, so I uploaded it to my tumblr blog: http://jimjams.tumblr.com/post/31045242364/wormies

    Reply
    • Great stuff, Jemma, and thanks for sharing a picture of your handiwork. Mark

      Reply
  • Hi Mark, Any thoughts on keeping the wormery indoors? I live in America, Indiana. Our winters can be bitter cold but I have a huge basement. Thoughts?

    Reply
    • Yes, indoors is fine – although you might want to look into a more sophisticated design than this one:

      Reply
  • Maybe a silly question – how do you harvest the compost and separate the worms out? Just pick them out by hand?

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    • Good question Simon I’ll answer fully when back from hols.

      Reply
    • Hi Simon
      If you wait till the wormery is full and then take the compost from the bottom it will not have too many worms in. If you like you can remove these by putting the worm compost in a riddle – the worms will burrow down (this is a reaction to being stressed by the upheaval of being taken out of the wormery) and you can collect them in a bowl underneath. Or you can spread the compost out over a sheet and put a bit of card over the central part – over an hour or two, the worms will all seek the shade under the card (they don’t like light), where you can collect them.
      Alternatively you can leave the worms in the compost – they’ll live in your pots and benefit your plants – this is what I always do unless there seem to be hundreds of worms in the compost I’ve removed.
      Hope this helps.
      Mark

      Reply
  • Basic question – how do you know when to feed them some more, and, do you ever need to add more water? Thanks for the great ideas!

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    • Good question Yolanda – I’ll do a post on looking afeter wormeroes when back fro, hols;

      Reply
    • Hi Yolanda
      if you see worms on the surface of the wormery when you lift up the card cover, this is usually a sign that they are searching for food – so would benefit from a feed. On the other hand, it the wormery smells bad, this is often a sign of over feeding. Little and often is usually the best strategy, particularly when you starting your wormery off. Once it’s fully established you can feed more.
      Yes, occasionally you may need to add water. the wormery should be damp – like a rung out flannel. If it’s drier than this, then sprinkle some water on.
      Mark

      Reply
  • My wormery in the Philippines is producing loads of compost. We also have a small bucket underneath to collect any liquid and use this for feeding plants in pots.

    Reply
    • Thanks for sharing that Yvonne – great to hear your wormery is successful, and the bucket underneath sounds a good way to collect the liquid.

      Reply
  • Thank you! I’m thinking of doing this with my son. I was wondering how many worms are added to be gin with? Are they OK during the winter (here in CA, it’s pretty warm year round) I love your accent!

    Reply
    • Hi Elka Worms double in number every 3 – 5 months and, eventually you want several thousand worms in a wormery operating at full power! So the more you start with the faster you will get there. I’d say 200 – 300 is the minimum really (unless you are very patient in which case you could start with less), and 500 – 1000 is even better. They are fine in winter in most climates – mine have lived fine through several cold winters in the UK. To be safe, you might want to insulate your wormery if you are going to have several days of freezing weather.

      Reply
  • Mark, this is great. Thank you for sharing. Fortunately, I work for a Council so have a few of these old recycling containers knocking about at home. I use them for picking up weeds, but they’re about to get a whole new life now!

    Reply
    • Great you’ve got some of those boxes to hand, Jono. They’re almost indestructible! When I lived in London I used to go down to the recycling centre where they’d often give me the old boxes. Apparently people used to bring them in and exchange them for the latest model!

      Reply
  • Thanks for this: I’ve also thought wormeries are more complicated than they are. I’ll have a go at making one soon…

    Reply
    • That’s great, Andy, do pop back and let us know how you got on.

      Reply
  • hi there, this piece is very timely -I’ve been thinking I’d like to make a wormery, so thanks. But how do you harvest the worm wee exactly?? cheers, jo

    Reply
    • Hi Jo, the simplest way would be to put a tray under the wormery to collect the liquid. If you have enough air running through the wormery, most of the liquid will evapourate to make a richer compost (that’s what I tend to do).

      Reply

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