Vermicomposting 101

A couple of days ago I posted a photo of the compost that I collected from my vermicompost bins.  40 lbs. of rich, dark compost!  And people started asking me how I did it.

The short answer is, I didn’t.  My worms did. 

The long answer is I read some books, watched some YouTube videos, bought some bins, bought some worms, collected some bedding, set up the bins, added the worms and let them do what worms do best – namely eat and poop!

A vermicompost bin is pretty easy and fairly inexpensive to set up.  You don’t have to do anything fancy – unless you want to.

I started with two 60 litre totes with lids and made small modifications to them.   Along the top under the rim, I drilled some air holes.  That’s it.  Worms don’t like light, so I used a solid coloured tote with a snug fitting lid.  Then I added some bedding:  leaves, cardboard that I tore into small pieces, some cow manure and a bit of dirt.  The dirt is pretty important as worms need grit to digest their food, sort of like birds, and the dirt is the perfect source for it. The bedding (cardboard, leaves and manure) provided space and warmth for the worms.  The space is important because it allows oxygen to flow through and oxygen assists in the decomposition process, making it easier for the worms to a) eat; and b) breathe!  Once the bins were ready, I added a pound of worms and some food and let them work their magic. 

Shredded cardboard makes
good bedding.

A bit of yummy cow poop, helps
get things started.

Grass clippings and leaves can
generate too much heat if added
when they are too fresh.  

Worm food is table scraps:  fruit & veggies mainly, but I also give my worms dried & crushed egg shells and coffee grounds.   Meat, dairy and citrus are not recommended,, so I avoid those.  But pasta, rice and bread are okay, too. 

Table scraps for feeding worms.  

The worms eat the bedding as it breaks downs as well, so it’s important to keep adding bedding.  Grass clippings or leaves are fine as long as they are not too fresh.  Fresh grass or leaves generate a lot of heat as they begin to decompose and that heat can disrupt the balance of the bin causing great discomfort for the worms.  They don’t like it hot.  They don’t like it too cold, either.  (Fussy little devils, aren’t they?) Over the winter when grass and leaves are not available, shredded paper is an option.  

Basically, if you have a not too hot and not too cold dark space with lots of bedding, food, oxygen and water, your worms will happily make compost for you forever.  I would advise anyone who would like to start a vermicompost bin to read up on it and/or watch YouTube videos for more precise directions than what I am sharing here. 

A simple bin like what I have described here is easy to start.  The problem with it is that once the compost is ready to collect, you have to remove it and that is a bit tedious.  So I switched to a flow-through system that makes gathering the compost much easier and much less traumatic for the worms.

A flow through system requires three bins.  The bottom bin is left intact without any modifications.  The second and third bins have holes drilled into them under the rim for air to get in just as I described above.  They also have holes drilled into the bottom.  When you are setting up the first  bin, it is important to put a layer of wet newspaper down on the bottom before adding the rest of the bedding.  This will help prevent the worms from crawling through the holes and escaping into the empty bottom bin where they will starve and die or dry out and die.  On top of the newspaper, add your bedding, food and worms, put the lid on and nest it inside the unmodified bin.  Make sure that the air holes are exposed and allowing air to get into the bin.  You can use a tray on the bottom instead of a bin if you prefer.  Just make sure that the bin is raised up a bit and not resting right on the tray.  This way worms that might think of venturing through the holes will be put off doing so by the light and any excess water can drain out fully.  

When the compost is ready to collect, start another bin by filling it with bedding and food (no need for the newspaper layer at all), nest it in the bin right on top of the compost and put the lid on it.  The worms will migrate up through the holes in the bottom and start working on the new bin.  Leave the three bins stacked like this for a couple of weeks to make sure the worms have all migrated and are settled in the new bin.  Then you can take the middle bin out and collect the finished compost. 

If you find water in the bottom bin, don’t throw it away.  This is called worm tea and it’s great for plants!

To collect the compost, leave the bin open without a lid in bright light for a while (a half hour will be more than sufficient).  If there are any worms left in that bin, they will burrow to the bottom away from the light.  Carefully scoop the compost out of the bin into bags or whatever container you want to store it in.  Once you have removed all the compost, put any worms that remain into the other bin so they can continue to fulfil their purpose in life.  Wash the bin and set it aside until it’s time to rotate the bins and collect the next batch of compost.

A stacking flow-through system makes
collecting finished compost easier.  With a third
bin (or tray underneath) you can continually
rotate the feeding bins and collect
"worm tea" at the bottom.

Check your bin often!  These are living creatures and they need to be taken care of.  If their environment gets too dry or too wet or they don’t get enough food or get too much, things can – and will! – go wrong.  Your worms could die and you’ll be left with a smelly mess of rotting gunk.  That’s not compost!

In a well-balanced, healthy environment, worms will propagate quickly.  Remember that their whole world is inside the limited confines of the bin, so overpopulation can be a problem.  You can harvest the worms and use them for bait or give them to other people for their own bins.  Or you can accept that many of them will die and become part of the compost. 

If you notice a lot of fruit flies or other bugs in or around your bins, that is an indication that you are giving your worms too much food.  There is, of course, a need for certain kinds of bugs in the process, but fruit flies buzzing around are just annoying.   Pay close attention to how much food your worms are eating and only feed them what they can consume in a reasonable amount of time.   Measure the food and monitor how long it takes the worms to eat it.  It won’t take long to figure out exactly how much and how often to feed the worms. 

When you feed the worms, cover it up!  Covering up the food with bedding material will help to keep the bugs away.  Chopping the food up will also help reduce the possibility of bugs because it makes it easier for the worms to eat it.  Large pieces of food will simply rot and bugs love rotting stuff. 

The actual compost that my worms produced over the summer.
40 lbs of nutrient rich soil enhancer!  

My worms produced 40 lbs of compost over the summer.  I was pretty pleased with the results.  But what to do with the compost now that it’s ready?  Well, some of it will be mixed with potting soil in the coming days as I transplant my house plants.  The rest I will bag and use in my garden later. 

I am hoping to start a proper worm farm in the near future that will produce worms, compost and worm tea for sale.  It sure would be a cool little business to have.    I just need to get over my squeamish aversion to touching worms.  I know it’s weird and irrational, but….  Ew! Eek!  Yuck! Shudder!