How To Make A Vermicompost Bin

July 19th, 2009  |  Published in Environment, Tutorials  |  21 Comments

Moving to a new town and starting 2 new jobs has not left me much time for crafting! I started teaching summer nature camp last week, and the kids, sun, hiking, and games are definitely taking up all of my energy. Whew! Luckily I get weekends to recover (i.e. lay around the apartment all day).

Today I finally got around to making a new Vermicompost / Worm Bin. Wooo! I’ve been living without a compost bin for a few months now, and I’m going crazy! Compost is one of my favorite things in the world, so I have put together this tutorial to make it one of YOUR favorite things, too!

Vermicompost bins are perfect for those of us with no yards, families with kids (and adults) who <3 worms, and really anyone who wants a simple compost system. The worms in a bin this size can eat 3-4 pounds of food scraps every week, so it can make a big dent in your trash load. The bin is super easy to set up, and these little hard working worms create a compost that improves the structure of the soil, acts as a disease suppressant, and balances pH. It’s great for your garden, your house plants, gifts for your neighbors garden, etc. Have I sold you on keeping a bin of worms under your sink yet?

The Worms
The worms that work best for a vermicompost bin are called Red Wigglers. You will need 1 pound of Red Wigglers to start a worm bin. These worms are happy to live in a shallow bin and are community worms that don’t mind being all clumped together in a small place.

You can ask at local garden stores and bait shops to see if anyone is selling them locally. If not, there are some online sources that will mail you worms. I just did a basic google search and found the following sites that offer Red Wigglers for sale. There are plenty more if these don’t work for you!

The Bin
You can really use any dark container that you can find for worms. I like to use styrofoam coolers because they are cheap (or sometimes even free at pet stores or fish counters – ask around!) and easy to poke holes into. You could also use wooden or plastic rubbermaid containers. For 3-4 pounds of scraps per week, the bin should be about 2′x2′x1′.

Poke or drill 1/4″ holes (pencil-sized) in the bottom and sides of your bin. I also added some to the top of mine. I like to err on the side of too many holes rather than too few. The holes allow oxygen into the bin so the worms can breathe, and also ventilate the bin to keep down smells.

Don’t be afraid to poke holes in the bottom! The worms are much happier in a dark, cool, damp, full of food space than out on your bright, dry kitchen floor. They won’t escape the bin unless conditions inside are really terrible. Without holes, the bin can become far too damp and start to turn anaerobic (yuck!).

Bedding
Worms like to burrow beneath a layer of bedding, so you should always make sure there is a nice thick layer on top of the bin. Bedding can be damp, shredded newspaper or damp leaves. You can use any paper for the bedding, but stay away from glossy or fluorescent papers. The worms will eat the bedding, so you will have to replenish it occasionally. Remember that the bedding should always be kept damp, not wet.

To start your bin, fill it 2/3 full of bedding.

Add Worms
Add 1 pound of worms to the top of the bin, and allow them to crawl to the bottom. Add a handful of sandy dirt to help the worms digest their food. My worms came with all of this dirt; you won’t need to add quite that much.

Cover Bin
Cover your bin with a piece of plastic or the original lid – worms like it in the dark! Set the bin on bricks or blocks of wood to give it better air circulation. Then place a piece of plastic or a tray under the bin to catch any liquid that may drip out. If desired, you can collect the liquid that drips out and use it as a fertilizer on your plants.

Bin Placement
Place your bin in a location that is dark and easily accessible. You will never use it if it is in an inconvenient spot. Place it in under the kitchen sink, in the basement, shed, or garage. You can keep it outside as long as it is protected from the hot summer sun, heavy rains, and freezing weather.

Feeding the Worms
Worms love fruit and vegetable scraps from your kitchen. Be sure to cut up large chunks of food to help it go faster. To feed them, lift up the top layer of bedding in one corner of the bin, place the food scraps in, then cover generously with bedding. With each new additions of scraps, rotate food burial sites clockwise around the bin. This way the worms can eat their way around the bin and distribute an even layer of castings.

I keep a little pin on top so I remember where I last fed them. I just have to remember to move the pin each time I add food.

Here is a list of what you should and shouldn’t add to your worm bin.

Good ideas:

  • vegetable/fruit scraps: peels, pulp, cores, leaves, etc.
  • coffee/tea: grounds, leaves, filters, bags
  • vegetable plate scrapings and leftovers from the back of the ‘fridge
  • stale cake and bread crumbs
  • cooked grains and cereals
  • egg shells

Bad ideas:

  • pet wastes
  • dairy products
  • fatty or oily foods
  • meat, fish and bones
  • anything non-biodegradable (plastic bags, twist ties, rubber bands, etc.)

Other Organisms
After you start to use your bin, you may notice other organisms besides worms living in your bin. This is normal and good! Worms tunnel through the compost to keep the bin aerobic (and therefore odor-free), quickly reduce the mass of material in the bin, and produce super rich castings. But they can’t do it all alone! They work along with bacteria, protozoa, fungi, and other insects such as potato bugs, springtails, and centipedes. These organisms will seem to come from nowhere, but they really came from the fruit and veggie peels, the soil you added in the beginning, the material the worms came in, etc.

Problems
Odor: If your bin starts to smell, it is probably because there is not enough air, too much water, or too much food in the bin. To solve the problem, make sure you have a thick layer of moist, but not wet, bedding. Fluff it up to restore air space. Stop feeding the worms until they can catch up to the amount of food in the bin. Always underfeed worms in a new bin until they are well established.

Fruit flies: The one organism that you definitely do NOT want in your bin is flies. To get rid of them, mix material in the bin, add a thick layer of new bedding, and stop feeding the worms for a week. When you start to feed again, make sure the food is always buried under the bedding and the bin is always covered.

You can also build a fruit fly trap. Pour some cider vinegar in the bottom of a jar. Make a small cut in the corner of a plastic sandwich bag, and rubber band over jar to make a funnel. Place the jar inside your worm bin. The flies will go in after the vinegar, but will be unable to fly out.

Harvesting Finished Compost
There are 2 main methods to harvesting the finished compost from your worm bin:

Push and Wait:

  1. Push contents of bin to one side.
  2. Add fresh bedding in empty half.
  3. Only add food in new bedding.
  4. Wait about a month for all of the worms to migrate to the new bedding.
  5. Harvest the compost from the old side once all worms have moved.

Dump and Scoop:

  1. Dump contents of bin into small piles on a piece of plastic under a bright light.
  2. Wait for the worms to clump at the bottom of the piles – they hate the light.
  3. Scoop finished vermicompost from the top of the piles.
  4. Return the worms to the bin.

Please ask me any questions that you have regarding vermicompost bins (or really any compost systems!). I am more than happy to help more people compost! I’ve worked with a lot of compost in the past, and even became a Master Composter in NY while in college, so I should be able to answer any of your questions. Happy composting!

21 Responses

  1. Jessica says:

    July 20th, 2009 at 6:24 am (#)

    This is great! I have a compost which has loads of fruit flies so now I know what to do to fix the problem:) Thanks for the tutorial.

  2. The Bewrwick Worm Farm and waste Systems says:

    July 20th, 2009 at 7:12 am (#)

    Good articl. I never thought to use coolers for a worm bin. i think the cooler would act like a insulator in the winter? Does anybody use the liquid that drains as a fertilizer?

  3. Recycle Raccoon says:

    July 20th, 2009 at 2:33 pm (#)

    We just made vermicompost bins with a group of boy scouts and discovered putting an inch or so of moss in the bottom of the bin allows the worms to retreat away from food and rest if need be. Also, if fruit flies are a problem even after all the tricks you mention it may make sense to reduce the amount of citrus scraps you feed your worms :-) Love these tips – I think we will use the cooler idea next time we do a scout workshop!

  4. Aisha says:

    July 21st, 2009 at 6:52 pm (#)

    Hi:
    Kristen Pellingra forwarded me your blog. We work together. I want to start composting with worms and live in a small apartment. I don’t really have anything to do with the compost, but want to reduce waste of what to do with the byproducts? Any suggestions? Also, can you use junk mail and magazine shreds as the bedding? Not sure if worms can digest varius types of paper beyond newspaper.
    Aisha

  5. Joanna says:

    July 23rd, 2009 at 12:12 pm (#)

    Um, I love your “You are loved!” pin. Just didn’t want that to go unnoticed. :)

    Oh yeah, and thanks for the composting tips too.

  6. Kerri says:

    July 29th, 2009 at 7:48 pm (#)

    We built an outdoor compost bin earlier this summer and have yet to use it- thanks for the inspiration and tips!

  7. Ashlee says:

    August 4th, 2009 at 9:14 am (#)

    Oh my word. I almost lost my breakfast. However, I very much admire your green efforts! I must find a way to do something similar without the worms.

  8. Kimmer says:

    August 4th, 2009 at 9:37 am (#)

    Would love to do this sometime, but have a few questions. Are eggshells safe for the worms? How long does it usually take for compost to be ready for “harvest?” What temperature range is ok for the worms? I’d prefer to keep them in the garage, but it can get pretty hot in the summer and pretty chilly in the winter!

  9. richard rowell says:

    August 26th, 2009 at 11:37 pm (#)

    Kimmer:

    Egshells are not only safe but required for my vermicompost bin. I have heard they act as a PH buffer or as PH up, not sure. All I know is if I have a bunch of worms “making a break for it” and nothing seems wrong, then I need to add eggshells again…

  10. Sophia says:

    September 20th, 2009 at 9:05 pm (#)

    I have maggots/grubs? why? I know they are okay for my compost bin, but they are really disgusting to look at. How do I get rid of them?

  11. gaurangjoshi says:

    November 12th, 2009 at 4:21 am (#)

    I learn how to reare the warms and you have best ideas and best future in vermi compost

  12. An Explosion of Worms . . . and Flies « Pragmatic Environmentalism says:

    November 18th, 2009 at 9:16 pm (#)

    [...] also going to add a fly trap to the bin. We’ll make one by putting an apple core in a jar, snipping off a corner of a [...]

  13. simplylogic says:

    March 25th, 2010 at 8:58 pm (#)

    Killing two birds with one stone, poor things :(
    Instead of moving the the Vermiculture and compost to my organic vegy pots, I simply planted the vegies in the worm bins. Works perfect and amazing quality and flavor of product including root crops, carrots and potato’s – worms don’t feed on living matter. A thickish,3-4in, mulch of straw, maize-husks etc, blocks out the light, retains moisture, provides adequate aeration, prevents any smell and keeps down any weeds. You must however retrain the cat.

  14. Julie says:

    October 28th, 2010 at 8:44 am (#)

    This is a GREAT idea!!! I have read about vermiculture before and as an avid fisherman I have been looking for a good way to keep my bait all winter long. Thank you for the info!!! =)

  15. Krysten Kelp says:

    February 1st, 2011 at 2:13 am (#)

    It’s a shame you don’t have a donate button! I’d certainly donate to this outstanding blog! I suppose for now i’ll settle for bookmarking and adding your RSS feed to my Google account. I look forward to new updates and will talk about this site with my Facebook group. Chat soon!

  16. Holly says:

    April 7th, 2011 at 12:41 pm (#)

    I have heard that styrofoam isn’t good to make a compost bin with. That it puts toxic chemicals into the compost. I was wondering how valid that is because I am planning on making these for a lesson in one of my classes. I am going go school for teaching so I will be graded for this and don’t wan to risk point being taken off by usin the wrong thing. I think usig the coolers is an awesome idea as I have some from using them to store things for a previous lesson and have been looking or a way to use them.

  17. Jolene says:

    June 29th, 2011 at 6:19 pm (#)

    Hi there,
    I started composting a few months ago with a little over a hundred worms (I went to free class and read YOUR webpage!), and have started to see a lot of brown stuff inside my cooler. I’m not sure if it is the castings or the coffee grinds I initially used… Do you know how one could tell? Or is it just that it takes time…and eventually I’ll know when there is a layer of it on the bottom? I guess what I’m saying is, I have no idea when I’ll actually have fertilizer to use! :-) Thanks!

  18. POORBA says:

    September 13th, 2011 at 3:01 am (#)

    It’s a great way you have told to keep our world clean. I shall tell to my friends also about you. May i post this on my facebook wall?????????????????????

  19. Lauren says:

    June 14th, 2012 at 11:08 pm (#)

    you should not use styrofoam. for anything. ever.

  20. irfan khan says:

    September 23rd, 2012 at 5:41 am (#)

    please send me the address of place where i get the plastic bag sized 12feet * 4feet * 2feet for prepair burmi compost. plz help me and give the link or address where i got it.

  21. amin parsa says:

    January 1st, 2013 at 12:27 am (#)

    How we can vermi compost in mass scales?

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