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 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!
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!).
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 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 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.
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.
- 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
- pet wastes
- dairy products
- fatty or oily foods
- meat, fish and bones
- anything non-biodegradable (plastic bags, twist ties, rubber bands, etc.)
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.
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:
- Push contents of bin to one side.
- Add fresh bedding in empty half.
- Only add food in new bedding.
- Wait about a month for all of the worms to migrate to the new bedding.
- Harvest the compost from the old side once all worms have moved.
Dump and Scoop:
- Dump contents of bin into small piles on a piece of plastic under a bright light.
- Wait for the worms to clump at the bottom of the piles – they hate the light.
- Scoop finished vermicompost from the top of the piles.
- 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!