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Making the compost |Talk to any organic gardener and you'll probably find a new method of composting. There isn't one correct way to make compost.
I use a method the basics of which I learnt from watching Peter Cundall on ABC's Gardening Australia. To make compost the way I do you'll need a frame, organic matter, water, air, some tools and someone to put it together. Here's how it's done.
First of all you'll need a frame in which to build your compost heap. You'll need 2 sections, each big enough to hold about 1 cubic metre of material. One is used initially for building the compost heap, the other is used for turning the compost. More about that later.
Ideally this type of frame could be constructed from green hardwood planks (like the one above), with 1/2 inch gaps between the planks for aeration. Avoid using treated timbers as the chemicals/poisons used to treat the timber may leach into your compost.
My frame sits directly on top of the soil, some people build them on a concrete base. This is worth consideration, particularly if you want worms in your compost. Worms have no role to play in the composting process I'm about to describe, so the base makes little difference.
I only make compost when I've amassed enough materials.
All of my family's fruit and vegetable scraps are saved up, as well as grass clippings, weeds, prunings and any other garden waste. If your neighbours don't make compost, then get them to donate materials to you. I'll use whatever manure is available, usually sheep, or chicken manure.
Pea straw is my favourite bulk material for composting, though it has become quite expensive and a bit of a luxury in Tasmania over the last few years. If I can't get cheap pea straw I use ordinary straw. Straw is made largely from carbon and because of this it takes longer to break down. It also locks up more nitrogen in the composting process than pea straw does. Nevertheless straw serves its purpose and still results in great compost.
Lime or dolomite can be used to sweeten the compost (neutralise the pH), and to assist the organic matter to break down. Blood and bone will enrich the compost with more nutrients.
Other organic materials like mushroom compost can be added but I prefer to add these directly to the garden beds as a mulch.
Now we have the frame and the materials, all we need is a hose, a garden fork, maybe a shovel and a rake, and last of all some muscle.
Build the compost in layers of different materials. First a 4 to 6 inch layer of straw, then grass clippings and weeds, followed by a 1 or 2 inch layer of manure, fruit and veg scraps, and lime if you have it. Give it all a soaking with the hose and that's the first layer finished. Now build another layer the same as the first and another and so forth until all of your material has been used. The ideal size of the heap is 1 cubic metre.
Over the next couple of days the population of organisms in the manure and green matter will be actively multiplying. This activity causes the heap to heat up and the organic matter begins to break down. The centre of the heap can reach temperatures of between 50 and 60 degrees Celsius. For a more scientific explanation of this process, you'll have to look elsewhere. Try one of the links in the Useful links section of this site. I ain't no professor.
After 2 or 3 days the heap will have gradually cooled and the size of the heap will have decreased markedly.
There are 2 options now. The first is to leave the heap for several months to break down naturally and with the help of worms, which will inevitably appear in your compost unless you have a concrete base.
The second, and my preferred option, is to turn the heap. This is simply a matter of shoveling the materials from one section of the frame to the other, mixing the materials as you go. This process aerates the heap and the heating process begins again. You shouldn't need to water the materials again, but if they're looking a bit dry give them a light sprinkle with the hose. The materials should remain damp but not soggy. Too much water negates aeration.
If the materials are turned every 2 or 3 days, your compost can be ready to use as a mulch in about 2 to 3 weeks.
The heating process has another benefit, it kills most of the weed seeds and pathogens. Worms on the other hand don't appreciate these high temperatures, but will quickly appear in large numbers in your soil when it's been mulched with your compost.
Successfully making a good batch of compost is one of the most rewarding aspects of gardening. In effect, you've created rich soil with materials many people would regard as garbage. Your soil will improve markedly with the addition of compost, as will the vigour of your plants.
I use compost in two different ways. First and foremost as a mulch. A few inches around a seedling goes a long way.
I also use compost to create no dig gardens. To do this, spread a generous amount of manure on the ground and cover this with a thick layer of damp newspaper. The manure will attract worms and will assist the newspaper and weeds in the topsoil to break down. Then I pile up to twelve inches of compost on top of the newspaper and plant directly into the compost. Instead of digging in manure for a new crop, I simply replenish the surface with more compost. Unfortunately, this method of gardening uses up a lot of compost and I rarely have enough available.