Supplies

The compost bin is comprised of 2 large, plastic paint buckets, a shower drain hair catcher, a hot tin can, an SOS pad, tape, peat moss and sand.

The concept is shown at the top of the page where my husband is gathering the finished compost. (That stage will be described later.) But basically, the worms live in the peat moss. The peat moss sits above a layer of sand that prevents the worms from burrowing further towards the bottom of the bin (and thereby drowning in the drainage water etc) The shower hair catcher sits in a hole in the bottom of the worm's home beneath the sand to allow excess fluids to drain into the second bucket. The two buckets are stacked, one in the other, with the second bucket acting as the "liquid gold" catcher. This liquid does amazing things on house plants, or if you are short on greenery, it can be poured down the toilet.

How many bins should you make? One is a nice start :) but it probably won't use all of your scraps, depending on your cooking style and frequency. As a vegetarian family of 3 (2 adults, one child) that cooks 5-6 nights a week from scratch, plus most breakfasts and eats leftovers for lunch, 6 bins is about perfect to utilize all of our scraps. Gauging it is difficult, but its always really easy to make one or two more bins down the line...

Cut Drainage and Air holes

After lugging your supplies home, assembling the bin is very quick. The first step is to cut your drainage and air holes. We've experimented with drilling multiple drainage holes with a drill and using various coffee filters etc as top ventilation. All of these approaches work beautifully, but honestly, take a lot longer to produce. We finally settled on using a shower hair catcher in the bottom to allow excess water to drain from the bucket the worms live and work in into the second bucket. And in place of the coffee filter we are now using an SOS pad, the worms can't get past it and it will keep the fruit flies away too while allowing ample ventilation into the worm's home.

We use a regular 14 oz tin can to cut the plastic. Heat it on a gas stove (use a hot pad!) and then plunge it through the center of the bucket's lid. Repeat this, heating it again, and create a hole in the center, bottom of the bucket too. This step stinks, literally. It didn't bother us before our son was born, but this time around the 3 year old and I went into another room and we opened all of the windows. I guess it all depends on how chemically sensitive you are because it didn't really phase my husband :)

Drainage hole

The hole in the bottom of the bucket is to drain the fluid run-off (the amount of which varies depending on what you put in the bucket) out of the worm's home so the peat moss isn't too wet for them. Place the hair catcher into the hole and this step is done.

Ventilation

The bin is almost complete. Place your SOS pad over the lid's hole and use your box tape to firmly attach the edges (leaving the center uncovered by tape, to allow for air flow).

Add the sand and peat moss

Now place about 1.5 inches of sand in the bottom of the bucket. The worms will not cross this barrier . Top that with the peat moss, leaving about 6 inches open at the top of the bucket. (Your worms will arrive in peat moss and once added should have about 3-4 inches of space before the lid.) Spray the peat moss with your kitchen or bath sprayer so that it isn't dirt dry. Leave your drainage bucket below for this step and lift the worm bin (top bucket) occasionally to check for run-off. Once water is dripping from the bottom, the bin should be adequately wet. The peat moss shouldn't be sopping wet, but should feel quite moist in your hand when you squeeze a fist full of it.

Add the worms!

We've always used Happy D Ranch Worm Farm for our worm supplier (no personal attachment, just happy customers). But if you google, there are Lots of options. Happy D worm's arrive in peat moss and can be added right into your bin. Pull a little of the peat moss back and pour the worms in, gently covering the mass of worms. You'll need 1000-2000 worms per bin.

Feeding the worms

Now to feed the hungry little buggers. We keep a large tupperware container (the label says it holds 19 cups) in the fridge and toss our scraps in as they are created. Your worms should come with a nice diet description (as well as a list of the other tiny critters that will call your bin home) that you can follow. But basically, no egg shells, no meat. Just like us, they do best with a fresh fruit and vegetable diet :) Noodles and bread are fine, but flour doesn't work well. Coffee grounds are great.

Our container holds the perfect amount to feeds our 3 worms bins so you can gauge your amounts based on that. To add your food scraps to the worm bin, pull the peat moss back, digging gently but deeply to form a trench on one side of the bin to hold the food. Put your scraps into the hole and gently push the peat moss back over the food so the top is flat again. Make sure to completely cover the food. The worms will do the rest!

Organizing your bin for your next feed and harvesting

We label our bin lids by number. The side that number is on denotes which side of the bin the food was added to last. We also keep the drainage bucket's handle on that side, a kind of double insurance. So the next time we go to feed the worms we first drain the liquid gold from the bottom bucket to leave enough space for the next batch of gold. (Its important to drain your bin so that it doesn't sit in liquid and become too wet for the worms.) We then switch the handle's side. (It is important to leave the side that was previously fed alone because the worms are very busy finishing off your scraps over there. That said, curious kids can take a look, just be gentle and always add new scraps to an empty side so as to not overfeed the worms.) This time, dig a trench on the empty side and pour your scraps in, carefully covering them with the peat moss that was pushed back.

Your worms will be ready for more scraps when the first side is scrap free. They work pretty quickly, but don't overfeed!

After 6 or so months have passed it is time to harvest your compost. The worm castings have to be removed from the bin and new peat moss added in to insure the worm's health (no one wants to live in their own, ahem, castings). The typical suggestion is to dig out the peat moss/castings and worms and pick out most of the worms. This takes surprisingly long :) Worms don't like to be hot or dry, so we use lamps to drive them underground. This approach takes a while too, but requires only a couple of minutes every half hour or so, versus crawling around after worms for the afternoon :) Its a good cold/hot weather activity when you are hanging around the house. But both approaches work.

Place a light just above an open bin (the clamp lamps sold at hardware stores work great). The worms will burrow down and after 30 minutes (or so) you can dig the top few inches of compost off - worm free. Repeat this process until you are low in the bin and there are tons of worms. At this point add new peat moss and feed one side of the bin and the whole process has begun again! The compost you remove can be added to your garden, to top dress your houseplants or donated to your local community garden.

Problem solving

This blog is just the basics. We've had so much trial and error (including the time we added a bunch of flour to a bin and ruined it and the time we had a bunch of escapees from one particular bin...) and also tried most mass produced models (and can remark on any questions concerning those) that we could talk endlessly about worm composting. But, don't worry, we won't :) Instead, just email us or put a comment after a post and we'll answer any specific questions you might have! Also, if you are tight on space, these bins stack 3 high quite safely. Just place small blocks (we used brio train track for the picture) on the lid of one (to allow air through the ventilation point) and sit your other worm bin on top.

Have fun and promote global worming!