Can-O-Worms canned

Kitchen scraps gathered in an enamel dish

About four years ago I bought a Can-O-Worms which I had sent from Australia where they're made. I seem to remember it cost about 16,000 yen. I also bought a big bag of worms from somewhere in Gifu for about 5,000 yen. The bag contained about 1,500 worms.

Can-O-Worms on the left with yellow bucket

At that time we had an underground concrete garage with a metal shutter and I kept it in there. The garage stayed at a fairly even temperature and because it was kept closed most of the time, it was almost free of flies. Since it didn't get very hot, the kitchen scraps didn't smell, unless you took the lid off and put your face inside, whereupon you could detect the smell of decay. But since flies rely on their sense of smell for their livelihood, they can detect that smell even if you can't, so chances are that if you've got your face in the bin checking the smell, a fly that has been waiting patiently nearby has also slipped in and laid some invisible eggs. These will hatch and then you'll have maggots in the bin.

With the Can-O-Worms in the garage, I usually had vinegar fly maggots and soldier fly maggots most of the time. Vinegar flies have a life-cycle of about one week, so there are always adults to fly up in your face to greet you, and always maggots on the go. Soldier flies are admirable creatures in many ways. The adults are quite handsome flies, they don't sting or do any harm, and the larvae are voracious eaters. But when you're trying to keep worms, having a bin full of large white maggots can seem a bit disappointing. Worm casts are supposed to have almost magical properties in terms of growing vegetables, but I've never heard anything to that effect about maggot poo. But because soldier flies have a long life cycle, they're not a constant airborne nuisance like the other flies.

The situation in the last house was tolerable. There were not enough flies around to bother anybody else in the garage, and there was no noticeable smell. I had a very small garden, so whenever one tray from the Can was full, it actually contributed a significant portion of additional soil. And this soil was quite a nice black, soft, inoffensive substance. The liquid 'tea' that dripped slowly from the tap also seemed to do the plants good. So for the couple of years that it was in the garage it was fine. During that time I tried a number of things to defeat the flies completely such as using shredded newspaper, sheets of newspaper, scattering rice husks on the surface, occasionally adding garden lime and so on. None of it worked, and the paper was just a big hassle.

Under the balcony

In the new house, the Can-O-Worms went outside under the balcony. Things started going wrong very quickly. In the cold season from October to April, the worms hardly ate anything at all. In the hot season, they ate, but the scraps were quite noticeably smelly, and there were lots of flies. The soldier flies found a way of laying eggs by scraping their little bottoms along the joins between the trays, and when the little maggots hatched, they were able to squeeze through, which they did in vast numbers. There was always a crust of yellow eggs between the trays. The 'soil' produced was not nice. It was a sloppy, fudgy mess with a generally decayed smell. And one tray doesn't go very far when you have some twenty plants as well as tens of metres of hedges.

A crust of soldier fly eggs

Legions of 'toilet flies'

Then at the end of last year, the bin became infested with little moth-like flies. Normally this kind of fly likes to sit alone on the damp towel hanging in the toilet of snack bars. But this time it came in Pharonic numbers. Every time I lifted the lid to put in fresh scraps, they swarmed out, flying up my nose, sitting on my eyelids, and churning dumbly about the concrete floor. I finally decided to try putting a piece of hessian sacking on top of the scraps, which all sources assure one is a great way for suppressing flies. Not only did it not have the least effect on the flies, it became infested with a very merry motley of moulds which degraded it into an annoying mess within about a month.

In your face

The procedure for swapping trays is not all plain sailing either. In theory, the worms are supposed to make their way up to the top tray in an orderly fashion. Well they don't. In fact, they rather like to hang about in the bottom tray of casts which are supposed to be mildly poisonous to them (just as we like to wallow about in bars which are mildly poisonous to us). So the bottom tray has to be placed on the top and the casts removed carefully with a trowel, as you coax the little worms down through the holes to the tray below with the 'fresh' food in it.

Managing the trays (awkwardly)

The trays, being full of a damp soil mixture, are heavy, and you have to lift two of them at a time to get the bottom one out. This is not very good for either the knees or back, whichever part you decide to sacrifice at the time.

Adult worms, baby worms, toilet flies, avocado seeds, eggshells, and sloppy casts

Well today, after much internal debate, I decided to can the Can-O-Worms. I just emptied out the contents of each tray into my two-bay compost heap. I was surprised to find that, after 16 months outside, there were in fact not very many worms in there at all. I think they must have been out-competed by the various fly larvae.

The compost heap however is full of worms anyway. And not just the red composting worms of the type that live in the Can-O-Worms, but the big snakey earthworms too. These attain spectacularly large sizes, so I assume they must eat a lot.

The fresher half of the two-bay compost has a preponderance of the red worms, while the more mature half has lots of the earthworms. This biodiverse situation seems more satisfactory than the monotype that the Can-O-Worms aims for but general fails to achieve.

So to sum up, claims that the Can-O-Worms of worms is fly-proof and easy to manage really are bunk. The suggestions presented for dealing with the problems that inevitably occur also did not work in my experience. However, with a small garden and somewhere enclosed to keep the bin, it may be worth having a Can-O-Worms. But whatever your situation, the same benefits can be achieved by composting and mulching, so I can only conclude that a worm bin is little more than a time-consuming curiosity.