Composing Compost: Fun with Microorganisms

So finally I completed the project that began with the chicken wire matters I spoke of a while ago. Work and such things have a way of intervening for weeks, preventing a good idea from going from conception to completion in what should be a day or two. The plan? To stop throwing away lots of wonderful organic matter and keep it instead, turning it into compost. This makes sense because so much of my garden has rather poor soil, for a start, and for a second matter it just seems wrong to not do it. for a third, it’s fun to do experiments with some microbiology for a change. Microbiology? Well, the object of the exercise is to let nature turn any organic material that you have into compost – full of nutrients for growing new things. Compost is also good for moisture control, good drainage, and a host of other things that are beneficial to plants in the garden. How does nature do this? Bacteria, mostly. But for the bacteria and other microorganisms to do their job (digesting the material), one needs to give them good conditions to live in. Conditions involve the right amount of moisture, air, and food, and the point of my project was first to prepare containment for the compost manufacturing process, and then to prepare a good combination of raw materials, place them properly, and then leave the little organisms to their own devices to do their thing. Here’s a good webpage at Cornell about the various stages of composting, the temperatures involved, and the various organisms (bacteria of various sorts, actinomycetes (a kind of filamented bacterium), fungi (various molds and yeasts), protozoa) that come into play at the various stages.

So, phase one: Containment. Well everything is going to be kept together with a cylinder of chicken wire, and so measurement of the desired radius [tex]r[/tex] followed by a quick computation ([tex]d=2\pi r[/tex]) to give me the length I needed to cut, and I was away. Shortly after I realised that my measurements were to be determined by the size of the mouth of the large trash bags I’d bought to add as the liner of the containment cylinder. So I ended up readjusting everything to fit that. I cut everything a bit big to allow for the overlap I needed to sew the thing into a cylinder after cutting.

I made two cylinders, about a foot radius (still can’t decide if this is a coincidence, or whether the fact that the strange measurement of 76 inches perimeter of the bag was arrived at because it gives about a foot radius circle). Slicing open the bottoms of two bags, I lined them (holding their folded over edges on with some clothes pegs – will get some bulldog clips for the job later). The finished containment chambers:

Then several days (two weeks, in fact) passed until today. Well, actually I did do some preparation last week. I put aside some clippings from some hedge work I was doing elsewhere in the garden. Today I took them out and began to prepare them. Basically, one wants a component of green matter in the mix, and so this was what I had here. A week away was supposed to have wilted everything and made it easy to get off the branches, but I’d left them in the bag, and forgot to put them in the sun for the week, so they were as freshly cut. Well, I bent my back into it, and put together a nice pile of small green bits – simply using my gloved hands to strip leaves off the branches. I used a pair of sharp clippers to help cut up some branch tops as well, so there’s leaves and soft short twiggy bits. Then I opened up the bags of dry brown matter that I’d gathered from various points in the garden for the last couple of weeks.

Thumbnail at far left: Essential bit of equipment – and standard issue for us eevill string theory practitioners – a pitchfork. Ok. It’s strictly not a pitchfork. Its heavier tines earmark it as a garden fork for digging…. but it’s, shall we say, in the same universality class as a pitchfork, and will do. 😉
A bit of mixing followed next. The plan is to get a good proportion of green to brown, along with some moisture (but not too much), and maybe a little bit of a kick start. I read a nice description of the mixing process, suggested containment, and some background material of the relative merits of greens (lots of extra nitrogen) and browns (lots of extra carbon) on this website, and followed their suggested layering method for helping getting a nice even mix, since it seemed sensible. I had some kitchen waste (vegetable skins and so forth) which went into the mix too. I also sprinkled in some handfuls of organic compost (E. B. Stone’s) that I had lying around, along with a few handfuls of top soil I bought a while back – the topsoil smelled a lot of manure, which is a good sign. Both of these latter should be rich in the right kind of bacteria, and so popping some in will help seed the whole mix nicely and help the processing begin. Moisture? I’ll leave it to your imagination to decide whether I sprinkled water or whether I brought myself to instead sprinkle Household Compost Activator (as described in the site I linked to above) from that watering can.

Before all this I’d spent some time trying do decide where to place the filled containers. First I thought I wanted them visible at the back of the garden, a pleasant reminder of the great stuff that’s cooking away inside, and the promise held for soil improvement all over the garden. In the end, I decided it would be better to put them out of sight, and so I placed them behind the fig tree (as is traditional!) and a giant cactus plant. There was just enough room there, and there’s a nice bit of shade from the sun too, so no fears about it drying out from too much direct sunlight. I put the bricks down, and two squares of chicken wire that I’d cut to place on top of them. This makes an elevated base for everything to sit on top of – air can get in through the bottom – the bacteria benefit from an air supply.

Well, after mixing and so forth, there was nothing left to do but fill the containment cylinders. That did not take too long. I ended up filling one (leaving room at the top) and having a bit left over in the next one. I pushed down with the long handle of the fork in a couple of places to make some breathing holes for the main batch. That smaller amount in the other cylinder won’t (probably) be enough to start composting on its own, so I’ll add it in later on after the main batch has cooked down a bit, or instead I’ll add it to a batch I start later once this one is on its way.

I covered them with squares of chicken wire (against critters) and left them for the night. If everything went well, in a couple of days the temperature at the core of the heap ought to be rather high indeed. The process will have begun.

We shall see.

-cvj