What is compost?
Compost is the breakdown of organic matter into soil particles. This process happens naturally on the forest floor, but can be accelerated in your garden by mixing specific ingredients in the right conditions.
A good rule of thumb is to mix four parts green material, such as grass clippings and kitchen scraps, with one part brown material, such as shredded prunings or dry leaves in small layers. You can also add animal manures and should keep the pile moist, not wet.
Cover an open bin to stop it drying out. It can take a few months to become dark, easily crumbled compost that can be used to improve your garden soil or added as mulch around plants. It is particularly good for improving sandy soil.
What is biodynamic compost?
Biodynamics is an enhanced form of organic gardening and farming and has been proven to increase soil fertility and the nutritional content of produce. Biodynamic compost is very similar to aerobic compost but with the addition of herbal preparations.
To begin the process, a spoonful of (containing cow manure that has been buried in the earth for three months) is diluted in water. Half the preparation is poured into six holes poked into the compost heap and the rest is sprinkled on top. This mixture attracts earthworms and helps to produce colloidal humus – a step beyond regular compost.
Colloidal humus is a pliable, nutrient-packed substance that is a constant source of food for plants. It’s formed when a colloid (a solid material suspended in liquid) binds with humus – the organic component of soil formed by decomposed plant material. Colloidal humus protects plants, promotes growth and improves flavour.
The principles of good compost
Gardeners often start composting with enthusiasm, only for their interest to wane as the results disappoint. Our guide helps you produce the best compost you can.
Composting is a naturally acidic process. Occasionally adding a handful of lime will aid in the decomposition of waste, encourage worm activity and discourage unwanted insect activity.
Compost should never be wet or dry, but should have the consistency of a wrung-out sponge. You may need to add water in summer as some composting units can dry out when temperatures are high.
Composting is like baking; to get a good result you need the right ingredients. Composting is easier though because there are only two main ingredients: carbon and nitrogen. You can judge how the ratio is going by the texture of your mix. If the compost is soggy with green waste, add some shredded paper or dry leaves. If it is too dry, add more leafy greens and soft prunings.
The ideal minimum volume for compost is one cubic metre. This size will generate sufficient heat to destroy weed seeds and speed up the composting process. Avoid adding weeds to smaller volumes as the seeds will survive the process.
Oxygen is crucial to a good brew. Turning the compost allows air to circulate and aids the decomposition process. For this reason it’s best to avoid adding materials such as grass clippings in bulk as they can mat together, blocking out air. Compost turning can be done with a fork or a special tool such as the Compost Mate.
It does not matter what ‘oven’ you cook your compost in, as the result is the same whether it is cooked slow or fast. Units with a larger capacity and good aeration generate the most heat and therefore kill off weeds more effectively and compost faster. Choose from an Aerobin, compost tumbler, compost cones and open bins.
- Accelerators and activators
Commercial compost accelerators add bacteria and fungi to the mix to help break it down. Do it on the cheap by retaining some of your compost for inclusion in the next batch, or adding a bit of garden soil, which will naturally contain these activators.
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