Vermicomposting in the cold-climate apartment - Vermidigestion

Input

Strained slurry from the Bacterial Filter system, soil from dead houseplants.

Output

Vermicompost – a mixture of regular soil and worm castings

Description

Tower vermicomposters are my bin of choice. My current model is three twenty-five litre (five gallon) pails stacked upside down on top of each other.

By stacking the pails upside down, the wider end is lower than the narrower end and the bedding falls more easily.

The stacked pails form a pipe of diameter about twelve inches and height about three feet. Raw material is introduced at the top; composted soil and castings are removed from a five-inch square aperture at the bottom.

The stack of pails sits in a vegetable drawer from an old refrigerator. There is no smell, no sight of worms, and no noise (!).

I introduce raw scraps (un-cut, un-pureed) or pureed pulp at the top. I may elect to cover new material with shredded paper or with composted soil from the bottom.

The worms gravitate to the new food source.

The worm population rises and falls within the tower, both numerically and geographically, as it struggles to maintain control of the food source.

Excess water seeps out of and away from the aperture at the base of the tower. There is no possibility of stale black mud forming, as I continually scoop material away from the base.

Harvesting the vermicompost

Soil, castings, and partially digested material falls out from the base of the tower.

I collect this about four litres (one gallon) at a time in a plastic pail, and spread it carefully on a mesh plastic plant tray.

After about fifteen minutes, most of the worms have migrated downwards, away from the light, and form a cluster in a small pile of soil and castings.

I shake the sieve gently, and most of the remaining soil and castings drop through. I try not to injure worms, and will pick them out by hand when I see them.

The sieve then holds undigested material – lumps of slurry, shredded paper, food scraps and so on. I return this undigested material to the top of the tower vermicomposter for further processing.

Now it is time to harvest the vermicompost. It is a slow and tranquil process, separating worms by a periodic trimming of the pile of castings to one side of the harvest tray. On one side I have a pile of castings and eggs, on the other side a small pile of castings and worms. I separate the worms (they will go to a nursery tub, to a houseplant tub, or be returned to the tower vermicomposter).

The remaining soil is rich in castings, but also holds eggs. I moisten the soil and set it aside in a plastic milk bag for four to five weeks to allow the eggs to hatch, at which time I make a final harvest, sending the baby worms directly top the tower vermicomposter where they can grow, gain strength, and mature.

The soil and castings is ready for export.

Thursday, August 06, 1998 – Three-stage composting

This summer I have experimented with three towers, running in series.

Out on the east-facing balcony I have two pails into which I tip my vegetable scraps. From time to time I add a layer of paper scraps. I maintain the few chicken and chop bones in a four-litre ice-cream tub in the freezer. If I dropped meat into the outdoor vermicomposter, I would attract flies and breed maggots. Once is enough.

The outdoor vermicomposter has a few residual Red Wrigglers which may feast, but my objective with the first stage was to allow composting (as distinct from vermicomposting) to take effect and dissipate the heat that can arise when raw scraps are added to a vermicomposter.

(That the tower is immediately beside the balcony door is a bonus – I can drop an apple core directly into the tower through the balcony door window).

Periodically I scoop partly-composted material from the base of this first-stage tower and transfer it to the second stage tower, the primary vermicomposter, which sits inside a closet, a series of twenty-five litre pails mounted on wooden legs, affording an easy drop of digested material from the base.

The third stage is a single-pail tower that receives material from the base of the second stage. This material consists mainly of dry vermicastings, and could easily be used directly to pot plants. I’m a skinflint, so I take the fall-out from the second stage, harvest the worms and eggs, and return those to the second stage – my main digester. The separated castings, with the odd scrap of pare and egg-shell, goes into the small third tower, where the remaining eggs hatch and feast on an apple-core which I add about once a week. This tower permits the compost to dry out to a manageable state, allows stray eggs to hatch, and provides me with a bunker of available soil for potting. I don’t have to sieve this output.

The three stages may sound like a lot of work, but I find it less work. Any discovered eggs or worms are transferred to the second stage. Any vermicomposting that takes place in the first and third stages is a bonus.

I deal only in shovels-full of material, and very rarely have to work through stuff with a teaspoon. That in itself is the main time-saver.

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