I understand that you are all desperately wondering how my worm farm is going. Well, friends, I’m about to tell you! Hurrah for you!
As a re-cap: here’s my post on how to make your own worm farm, and also what to do if they all die in the heat of Summer (if you can’t be bothered reading that post, the precis is: “Nothing”). And as inspirational reading, may I suggest my review of This Book, and also This Book. (And then, of course, you should actually go read those books; they’re wonderful.)
I constructed our* worm farm about this time last year. Aside from the despair when I thought I had killed all of them in December, all has been going well since. We have “harvested” two containers of worm castings to use when potting plants.
As an aside: Gardening has actually been really difficult because barely anywhere gets reasonable sunlight. Our home is west-facing and a neighbour abuts us to the north, so our outside space is west, south and east. We have a high fence all around; great for privacy but terrible for sunlight. From about April, barely any patch of the concrete around our house gets any sun at all. What few plants we have are on tables gleaned from other people’s hard rubbish. Still, I have a dwarf Meyer lemon doing okay in a pot (I move it around quite a bit to try to catch some sunshine for it) and some herbs, lettuce and beet leaves struggling through winter, but I expect they will all revive when the warmer weather comes. (Soon, I hope. Melbourne winters are terribly dreary. Yes, more so than English winters, where the ever present hope for snow kept my spirits childish.)
In 12 months we have filled four polystyrene boxes. Two before winter (one inactive and one active; both became excellent compost before winter arrived). Winter slowed the worms down significantly and also made “harvesting” the worm castings more difficult, so I kept two boxes on top of each other (the bottom inactive and the top active), until last weekend when it was getting desperate as the top active bin was full. I had been being a bit cheeky and adding to the inactive bin, too, but I needed to leave it alone for a bit if I intended to clear it of castings and swap it with the active bin.
How does one go about harvesting worm castings? I like the lazy method:
Step One: Wait until the entire box looks like clumpy potting mix, and most of the worms have left it to migrate to the active bin. This is harder if you add egg shells and large pips (like avocado and stonefruit), as they take longer to break down and continue to provide the worms with food even though you have ceased adding fresh vegetable scraps. With the food, there’s no incentive for the worms to leave the inactive bin and move to the active one. It took about a month after I had stopped adding fresh scraps for one filled polystyrene box to turn into nicely composted matter (humus; but no, not that kind).
Step Two: On a nice, sunny day, tip the box of composted matter onto a plastic surface – a ground sheet; a bin lid, – whatever you have handy (newspaper is not a good idea) – and heap it into a volcano shape.
Step Three: Wait a while. How long you wait will depend on how warm it is. What you are doing is working with the worms dislike of light and heat. The worms will head into the centre of your humus volcano. The first time I harvested, it was hot (late 20s celsius; I have no idea what farenheit) and it took barely any time at all for the worms to disappear from the top and edges of my humus volcano. The second time I harvested, the worms were a bit slower but again, I could see them quickly burrowing away from the terrible sunlight and heat (early 20s celsius; still no idea what farenheit). Last weekend, the worms couldn’t really be bothered. It was neither bright enough, nor hot enough (early teens celsius; you guessed it, still no idea farenheit) for them to do more than leisurely burrow a centimetre or so from the surface of the humus volcano.
Step Four: If your worms have diligently burrowed into the centre, you can scrape away the top and sides of your volcano away and use as potting mix / compost. Then, heap the volcano up again and wait again. Repeat until there’s nowhere for your worms to go and you’ve had enough of torturing them for the day. Reward them by depositing them into your active bin.
Step Five: Now you have a clear bin and when the currently active bin gets full, it becomes your inactive bin and the bin you’ve just cleared becomes your active one.
Alternative Step Four: If your worms have not diligently burrowed into the centre of your humus volcano, scrape little teeny tiny bits away from the surface and edge of your volcano; heap up your volcano again and repeat until you lose patience. I harvested perhaps a 15cm diameter pot of useable, worm-free compost in this manner after a frustrating couple of hours last weekend. Eventually, I gave up (also, the sun had completely disappeared and it looked like it would rain. Later, it did rain. Why, yes, I do live in Melbourne.)
Alternative Step Five: Return your humus to the bin (not the active one but the one you just emptied). Push the humus to one side and construct a newspaper wall. Punch some holes randomly into the newspaper wall. You now have about two-thirds of a box to be your new active bin. Place this on top of your very full other bin and hope that it will take you at least a month to fill up two-thirds of a bin. Hope, also, that it will be nice and warm next time you have to harvest your worm castings.
And here’s my hot tip on trouble-shooting your worm farm: newspaper. Solves every worm farm problem.** Basically, tear up a few sheets of newspaper; toss them in; put the lid back on and DO NOTHING ELSE (including do not add scraps) for a week or two. Check, and if the problem’s gone away, continue adding scraps. If the problem’s not gone away; repeat.
** I’m not saying this is the only way to solve worm farm problems, but it’s the only thing I’ve done and it seems to work fine. If I cannot add stuff to the worm farm, then I freeze and add when I can.
(* Recently my partner was chopping up the vegetable scraps and said, “Look how well I’m treating your worms.” And I replied, “OUR worms. How well you’re treating OUR worms.” Because they are.)