Creating and maintaining a compost heap.

Compost is one of the best and cheapest ways of adding nutrients back into the soil in your garden, improving soil structure, acting as a mulch to reduce moisture loss, as well as being perfect for filling pots, planters and hanging baskets without having to lug huge bags of compost from the garden centre.

There are four main types of compost bin - tumble bin, pre-fabricated, heap and build your own. All achieve the same result and use the same basic techniques, layering fleshy organic waste and dryer woody material, adding a small amount of liquid and covering to generate heat.

Pros & Cons

The 'tumble' and 'pre-fabricated' bins are easy to erect and keep the heat in the heap and the rainwater out. Capacity can be limited with these types.

The 'heap' and 'build your own' are obviously cheap to make but can take longer to produce your finished compost.

Warning - Watch your shins when using tumble type compost bins - if they don't do a complete revolution it can swing back and hit you - I've done this twice now and it hurts like you wouldn't believe.

Making compost using a homemade bin:

  • The heap should be as big as you have room for (at least 3ft wide by 3ft deep and one heap is better than two smaller heaps). It's often recommended that you have 3 heaps, one that you are adding material to, one that full and is cooking and the third that you are taking material from.
  • Pretty much any organic material can be added, including grass clippings, weeds, straw, manure, shredded newspaper, kitchen waste, plant cuttings and prunings.
  • Compost heaps break down material quicker if they are built up in layers. Start your heap off with 9" layer of grass cuttings and weeds into the bottom, making sure that this layer is level rather than heaped.
  • Add an inch of material high in nitrogen, such as horse or chicken manure. Then add 6 inches of course mixed waste, shredded branches, straw, twigs, vegetable peelings, eggshells etc. wetting any dry material.
  • Sprinkle on compost accelerator - human urine is perfect for this.
  • Keep adding in layers until the heap is at least 3 foot high.
  • Cover with an old piece of carpet or polythene to keep out the rain. Rainwater will cool the heap and also stop any bacterial activity.
  • The compost heap should start heating up and steaming after a week. The high temperatures will kill any weed seeds. Turning the heap every four to six weeks will allow air into the heap accelerating the composting process.
  • Once your compost bin is full and working, start another heap. If you continue to add waste to a compost heap you will compact it, expelling air and stopping the composting process.
  • You should have perfect crumbly compost in six to nine months that you can put straight on to your beds and borders as a mulch or top dressing.

Any material that hasn't broken down can be put back on to your new heap.

A good compost heap should be an average of 70o C and will kill most pests and diseases. Put any diseased plants and fruit into the centre of the compost heap and surround with green material. But if in any doubt, with things like bindweed or knotweed, put them on the bonfire.

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