Composting in the City

A compost bin or pile in the garden can work really well but it is also possible to compost in a very limited space such as a courtyard, balcony or even a kitchen bench top.

 

© Scott Hitchins

For most of us, when we think of composting, we think of a black bin in some obscure corner of the garden where, when we remember, we go to empty a container of kitchen scraps into a smelly slimy morass that seems to go forever without breaking down into the lovely rich soil-like stuff that TV-gardeners are always running their hands through as though they’d just discover a treasure chest full of gold coins.  This compost bin or pile in the garden can work really well but it is also possible to compost in a very limited space such as a courtyard, balcony or even a kitchen bench top.

We all know by now that composting is a ‘good’ thing. It keeps organic materials out of landfill, thereby reducing the production of Methane (which is much more destructive to the climate than Carbon dioxide). However it also makes good economic sense:  Any food which you don’t get to eat this time around, you can compost and use to grow more food, giving you a second chance to get value out of what you’ve paid for.

When asked about the reasons why they do or don’t compost, some common issues people have are:

  • It smells! Not true: a properly running compost system should smell pleasingly earthy.  The most common reason for smell is that the system is too wet or contains too much ‘green stuff’ and not enough ‘brown stuff’ and not enough air is getting in.
  • It attracts creepy-crawlies!  Some insects and other little creatures are a normal part of composting: slaters and worms help break down the compost for you and increase the ration of good microorganisms.  The little vinegar flies zipping about when you open the lid are also part of the process. They are not the destructive fruit flies that we get in warmer parts of Australia (although, they are close relatives with some really cool biological characteristics).
  • It attracts rats and mice! If you turn or move your compost bin and see little mousies running around, your compost is too dry. They can’t live and breed in a properly damp (but not wet) compost pile.
  • Everything goes mouldy!  Well, der!   That’s the whole idea: microscopic plants, animals and fungi consuming the waste and growing: exactly what happens on the forest floor.

Inoculate your own Bokashi bran

The expensive part of using a Bokashi system is the ongoing cost of the sprinkly stuff. Beat the system and make your own.  For those of you who make your own yoghurt or sourdough at home, you will find the method quite similar:

Mix together three parts ordinary generic wheat bran with one part brown sugar or molasses with a good handful of the expensive bokashi stuff you bought (or some homemade stuff from your last batch). Add enough water to make it quite damp: if you squeeze a handful of it, no more than a drop or two of water should come out. Pack it very firmly into a lidded container, seal and leave in a shady spot for a month or more.

Hints

(adapted from http://journeytoforever.org/compost_make.html)

  • Not enough water is better than too much water. Too much water is a usually a disaster, but if there's not enough, the pile will heat up and then stop. Empty it out, loosen it all up with the compost fork, add more moisture, and put it back in the composter again, no big deal. Soon you'll learn how much water is enough. If your pile is too wet, try emptying it, fluff it up, add more dry stuff, and some dry greens if you have such a thing (blood & bone or bird poo), and rebuild it.
  • Too much nitrogen is better than not enough nitrogen. If there's not enough the pile will just sit there forever, nothing happens for a year or two. If there's too much the pile will heat up well and simply out-gas the excess with the steam in the form of ammonia gas, until the balance is right. Useful additions: Garden lime or dolomite, the finer ground the better. Liquid seaweed emulsion, such as Seasol or any other brand: - all the minerals for all the microorganisms, in easily digestible forms. Add compost from the previous batch to inoculate the pile. Sprinklings of ground rock powders are useful.

Other areas to explore:

  • Compost teas –either fresh or brewed and aerated
  • Trench and Sheet composting
  • Hügelkultur
  • Electric composters