This afternoon I attended Kiama Council’s Composting Workshop, held at the Girl Guides’ Hall down in Hindmarsh Park. It was run by Josephine St John, council’s Waste Minimisation Officer.
What a great event!
I had really thought I wouldn’t learn much from this workshop, but I thought it was a good opportunity to meet some interesting people and maybe pick up a few little tips. It turned out to be full of useful information, and well worthwhile.
Kiama Council is currently doing random audits of household rubbish put out for roadside collection. They’re doing 260 samples across the municipality to get a handle on what kinds of waste people are generating and whether they’re recycling properly.
They’ve found that around 63% of household waste in Kiama is organic, and therefore potentially compostable. That seems really high to me, but they’ve sampled and measured it and that’s the figure.
Anyway, on with the composting tips…
All the compost info you read talks about ‘greens’ and ‘browns’. Greens supply nitrogen, and browns supply carbon. You generally want 1 part green to 2 parts brown to get complete breakdown. Too much green and your compost will go slimy, acidic and smelly. Too much brown and it won’t break down very quickly.
It’s good to compost your weeds, since they’re plant matter and will break down nicely. However, if your compost heap doesn’t get hot enough to kill the seeds, you’ll have weeds sprouting everywhere you spread the compost. To get around this, put all your weeds in a bucket. Pour boiling water over them until they’re just covered, then leave for two weeks or so. Pour off the water and use it as a liquid fertiliser, and tip the remains of the weeds into your compost. The seeds won’t survive this treatment! And if you want extra ‘green’ points, rather than boiling up all that water using electricity, use one of those outdoor solar shower thingies to heat the water.
Collecting seaweed from beaches in Kiama is legal, as long as you keep it to less than 5 kg at a time. I had heard elsewhere that it was illegal in NSW, but Josephine assured us she’d done the research and it was OK. You just rinse the seaweed off and dry it on the clothesline for a few days, then add it to your compost as a ‘brown’. Seaweed is great for adding trace elements that are often missing from other sources of compostable material.
Tumbling bins are OK, although they generally don’t let in as many beneficial microorganisms and other critters because they’re not in contact with the ground. One way to improve this is to make a compost tea from your traditional compost (just put a few handfuls of compost into a hessian sack and sit it in a bucket of water for a few days), then water the tumbling compost bin with that. It’ll introduce lots of beneficial Effective Microorganisms (EMs) and help break the compost down quicker.
Some people mentioned problems with kikuyu grass growing into their compost bins. One way to prevent that is to grow comfrey all around the base of the bin. Comfrey is a great barrier to grasses, is great for adding to the compost as an activator, and it will slurp up any nutrients leaching out of the bottom of your compost bin.
Josephine recommended you not compost rhubarb leaves because they’re poisonous. This alarmed me, because I’ve always put them in. A bit of research (e.g. here) showed that it’s actually OK, as long as they are composted completely. The poison in rhubarb leaves is oxalic acid. This breaks down in the composting process pretty quickly, and won’t cause problems for either the compost heap or the garden when the compost is spread out.
The worm farming part of the talk was interesting, although not much new information. It is interesting to note that the worms don’t actually eat the scraps you’re putting in, they feed on the microorganisms that eat the scraps. Also, blending the scraps before putting them in can greatly speed up their consumption.
I was amazed to learn that underneath Shellharbour Workers’ Club is a massive worm farm! All of their organic waste from kitchens etc is dropped down into the worms, and a guy comes 2 or 3 times a week to check up on everything and keep it all chugging along. Presumably he sells the worm castings or something.
The final part of the Composting Workshop was on Bokashi, and this seemed to be what nearly everyone was there for. I had read about it before, but was interested to learn more and to see it in action.
Councils all over the place provide subsidised compost bins and worm farms to their constituents, but Kiama Council is the only council in Australia that also provides Bokashi supplies.
Bokashi is basically a way of fermenting kitchen waste in an airtight bucket. You put in your scraps, push it down to exclude as much air as possible, then sprinkle the Bokashi grains (a special grain mix innoculated with EMs to to start the fermentation and breakdown process), then seal up the Bokashi bucket. Every couple of days, you add more scraps and grains and seal it up again.
Over time, Bokashi juice collects in the bottom of the bucket. This can be drained off via the tap on the bucket, and is an excellent plant fertiliser (diluted well, 1:100). The juice is also apparently good as a drain cleaner or a septic system activator.
Once the bucket is full of kitchen waste, it is left to ferment for another couple of weeks and then buried in the garden. When it hits the soil, earthworms and other creatures will come from miles around to feast on it, and it is broken down within a few weeks. Many people bury it in a trench in their vegie patch, and then plant over the top of it to give the plants a good boost.
Council sells the Bokashi buckets for $70 each to Kiama residents (they’re normally $99), and the grain refills for $7 per kilo. Hmm, perhaps they’d make good Christmas presents…
Oh, and we also got some swag for attending. We got a voucher for a free compost bin, a KiamaSphere coffee cup, and a reusable fabric shopping bag containing packets of flower and vegetable seeds, a pen and pad, a nice folder for keeping handouts in, and a bunch of handouts and brochures on composting and other environmental initiatives. Cool!