off by one for 2008 September 28 (entry 0)

< flynn's arcade -- akasha restaurant in culver city
solanaceae >

[Trackback URL for this entry] Sun Sep 28 16:19:57 PST vermicomposting:

I like to grow plants, and I like to recycle. It only makes sense then that I would want to start composting. Unfortunately, we live in a small apartment with a small outdoor porch. Not enough room to do traditional composting, not to mention the smell. Enter vermicomposting, in other words composting with worms.

Composting with worms is great because it is fast, low odor, easy, doesn't take a lot of effort, and doesn't take a lot of room. You'll be amazed at how fast and how much those worms can eat.

There is a lot of information online about vermicomposting, where to get red wigglers, and more. I'm not going to try and recreate that information here (oops, I guess I did, sort of). What I do want to talk about is my method, which is small, cheap, easy, effective, relatively odor free, and low effort. I have my worms set up year round in the shade of our porch (we live in LA so it never freezes here), but you could do this in your basement, or whatever you like.

The simplest vermicomposting setup is a box with drainage (to catch the runoff that seeps out the bottom). Basically, you put your garden greens, veggie cuttings, grass, etc. and safe paper or cardboard into the tub. The worms will eat it and poop it out as very nice fertilizing dirt. As they eat what you put in, you get dirt back and more room for more input. (As mentioned above, you will sometimes get brown liquid out the bottom which, while smelly if disturbed, is also incredible fertilizer in its own right.)

You have to make sure that the worms get enough food and "bedding", which is things like cardboard, dried leaves, etc. In composting parlance they call it "green" (fresh material) and "brown" (things like newsprint or egg cartons). Think of it this way -- if it was all lettuce and tomato stems, it would get pretty rotten and mushy. The dried "brown" stuff keeps things balanced. If it seems too soupy, add more brown. If it seems to dry, add more greens or some water. No big deal.

The hardest part about worm composting is separating the good fertilizer from the worms and uneaten stuff -- the worms do all the work but they don't put it in bags for you. They will, however, move toward food and away from thoroughly digested material. Leveraging this principle, there are lot of kits and contraptions that make it easier, and you can fish around in a single tub although it's kind of a hassle. Many of the kits have drawers or separate partitions for the worms -- and that's what inspired my system.

I needed this to fit on my porch, so I went with a smaller size -- you can try adjusting the dimensions.

What you'll need: 4 12"x18" rubbermaid tubs and 2 lids (total) for the tubs. Some dirt, garden waste, and "brown" material for starters. You will also probably want to order some crushed lime (pulverized sea shells) online, and finally, enough fabric and a long (e.g. 30") zipper for a giant bag to put the whole thing into. Oh yeah, and some worms -- you can order these online too, or get some from a friend. Regular earthworms are not what you want -- you want "red wigglers".

(Note: red wigglers are considered invasive species in some areas because they can eat the leaf "litter" on forest floors which is needed for some other species. PLEASE be smart about your use of red wigglers.)

The basic idea is simple: The worms leave "finished" areas and move towards new food. So we're going to fill a tub, stack a new one, and keep going until the 4th tub is full. By then, the bottom tub will be "finished" and most of the worms will move up to the 2nd to the bottom tub or higher. Then all you have to do is harvest your manure and use the newly emptied tub for your new top tub.

See my photos which should help answer any questions you might have.

First of all, drill big holes all over the bottoms of all four tubs. I used a large 1/2 inch drill bit, but you can use whatever your largest bit is. You don't want to make the tub unstable, but you want it to have plenty of holes for the worms to migrate through. Then, take a smaller bit and drill many small "air holes" in ONE of the lids you bought and in the sides of the tubs. (See pictures).

Now, take the other (undrilled) lid and set it on the ground, upside down. Take and put your first bin on top of this lid, open side up. (This lid will serve as the catch tray for any juice (we call it "worm tea" in the business). Be forewarned that this does not actually hold that much juice -- if you're doing this in your house, you probably want a larger catch tray.

Put all your worms and food, etc in this bin, and put the lid you drilled all the holes in on top of this bin as its lid (this won't keep bugs out, but it may keep critters out). Fill this tub up until it is jam packed full (this takes the two of us about a month or so -- see below for how we fill it). When the first tub is full, we're going to add a second story to your worm tower. Take the lid off, take a second tub and set that tub on top of the full tub, and put the lid on. Do this until you've filled all four tubs.

While it might take your worms a little while to reproduce and catch up with all the food you're providing, you can periodically check on your lower tubs and see how they're progressing. Resist the urge to mess with the contents of those tubs by stirring them or adding more stuff to them. Just keep an eye on them and see that they're still moist and still getting eaten. Also, don't worry that the tubs will settle -- this only makes sense as the food is broken down that a tub that was once full to the brim is only half full of manure. The idea here is that it's no fuss, no muss. Don't muss with it.

Eventually, your 4th tub will be full, and you'll need a new tub to put on top. Here's the cool part. We're going to empty the bottom tub, and put it on top! Voila! So, at this point, you can stir the tub a little and see if it looks like it's pretty well used up. If it's NOT, give the worms a few more weeks to work and let them catch up. I'm at the point with my system that by the time I get to the top of my 4th tub my bottom tub is ready. You could also add a 5th tub, I suppose. Whatever works for you.

Here's how you get the manure out -- and this is the most time intensive job.

The worms hate light, so they will dive when exposed to it. Take the bottom tub and set it out in the light. The worms will dive in a few minutes, and you can scrape off the top layer of dirt until you start seeing worms. Then, go have a cup of coffee, and come back in 10 minutes and scrape the next layer off. Eventually, you'll get down to mostly worms (or just be ready to quit). You can dump that stuff in the top tray, or just add your new food to whatever's left over. To be honest, this is kind of a lazy job you do while doing something else. A watched worm never dives, so don't expect to just sit and do this in one quick session.

That said, you may find so few worms in the bottom tray that you're happy to just dump it all out. Root around in there first and see. You'll also find small little translucent, leathery sacks in there (about the size of a styrofoam grain) -- these are worm "casings" -- little egg sacks. You really can't worry about sifting them out if you're going for my "no fuss, no muss" strategy, so don't. My other advice is, don't get attached to the worms. Some will die, some with get thrown out. You'll spend a lot more time if you agonize over the worms, and it really doesn't matter: losing a few won't hurt your bins, and if they make it into your plants, who cares? They won't hurt your plants.

What's with the fabric and zipper? Well, on my porch in Los Angeles, if I don't do something, my worm bin gets swarmed by fruit flies, and this cuts down on the enjoyment factor a whole ton. So I made a giant "pillowcase" with a zipper that I zip the whole thing up into. Voila! No fruit flies! You don't need a pattern to do this -- just make a big bag. It doesn't have to look pretty or even be particularly straight. I made mine in about 15 minutes. (See photos.)

You may find other "helpers" in the bin working on the material. I have a lot of little mites -- the vast majority of which are not worth worrying about. Pill bugs might also find their way inside (these are often called potato bugs because they look like little gray potatoes), and they are also friendly. The grossest thing I've seen have been soldier fly maggots and although they are nasty looking they are also friendly and won't hurt your worms. Soldier flies are big and ugly, but they do not bite or otherwise affect humans. Using the big cloth bag keeps out bigger pests like pillbugs and soldier flies.

A few final tips:

Buy some crushed seashells. The acid environment of the breakdown is part of what makes it smell bad. So when I add new food, I almost invariably shake the white lime all over the new food and this drastically cuts down on smell. You can also use BBQ ashes for this purpose. Lime is cheap and can be found online.

You can also used crushed eggshells -- another great resource to reuse rather than throw away. You'll probably want to grind them in a blender, food process, or mortar and pestle, since the worms don't really "eat" the eggshells.

Get a bin to store your food in. It's a waste to feed them every time you have a tomato stem. I have a (roughly) half gallon plastic container with a snap-top lid (no smell!) that we keep under the sink. I feed the worms once its full. It gets a little juicy in there, but that's ok -- a little breakdown before feeding just speeds the process along.

There are things you DON'T want to feed the worms. First, stick to veggies and "brown" material. Don't put meat, dog poop, oils, etc. In short, don't put anything in there that could rot and get rancid. Secondly, there are some things they don't really like, such as orange peels. Banana peels are supposed to be very bad because of the pesticides. Onions and broccoli are somewhere in the middle. Basically, you'll figure out what they like and don't like. But citrus peels and bananas are a nono.

Don't add plants with seeds you don't like. For example, if you cut down grass that's gone to seed and feed it to your worms, they will not eat all the seeds, and so you might inadvertently be seeding your plants with your compost. We feed almost exclusively garden waste, so I don't mind the few volunteer plants I get like green peppers and tomatoes, but maybe you do. Also, don't feed the worms soil or plants with pests like scale or mold. The worms will not combat the pest and so by using the compost you may inadvertently be innoculating your other plants.

There are things they LOVE. For example, our coffee grounds AND filters (they're "brown" material whether they're bleached or not) go in every day. I also put our napkins and paper towels in the tub (if they don't have formula 409 on them or whatever), so that by the time I feed them, I'm already adding "green" and "brown" at the same time. I don't even shred up the napkins. It takes too long and the worms don't seem to mind.

There are other kinds of "brown" you can put in -- newsprint, egg cartons, paper towels, napkins, etc. It matters a little less if you're not eating anything from the garden, but newsprint and egg cartons are OK because they have stricter controls on safety (newspapers use non-toxic soy inks, for example). Of course, things like paper towels and napkins have to be safe for you to wipe your face on, so those are OK.

Don't use glossy or office paper. You may find that they don't like certain kinds of leaves (mine don't like lime tree leaves). They also don't eat wood -- so don't put in twigs, etc -- they won't eat them. That said, adding some sawdust to the mix would be good for the soil you get out.

Of course, the smaller the size of the food particles, the faster the worms will eat it. Some people chop or blend up their stuff before adding it. This obviously uses MORE electricity, so it kind of defeats the purpose. I even did this for a while, but it honestly was more work and in the end I found having enough tubs gave the worms plenty of time to do their thing -- I didn't need to chop the food any more finely.

So, what do you do with the stuff once you get it out? Well, you can add it to soil as a fertilizer. I just put it on top and water over it. You can also dissolve it in your watering can -- the muddy brown water that comes out is a great organic fertilizer. You can mix it in with other soil, or throw it on your yard, give it to your neighbor, etc. I make more than I can use -- and you probably will too.

While you think about how to use your rich, black, fertilizer, just imagine to yourself this wonderful resource sitting in a toxic landfill for hundreds of years -- isn't this better!

If you have any questions, just search online or email me: pedro@tastytronic.net.


[Main]

Unless otherwise noted, all content licensed by Peter A. H. Peterson
under a Creative Commons License.