What is Compost?
Compost is rotted (decomposed) organic material
Why make Compost?
It’s good for the soil
It improves soil structure and water retention, reducing the need for watering and fertiliser and encourages worms and micro-organisms (bacteria and other small creatures)
It helps plants grow better
Adding compost to soil gives plans nutrients they need to grow well and have more resistance to pests and disease
It helps the environment and saves energy and resources
Reduces waste going to landfill – where it produces methane, which contributes to global warming
Removes the need for peat-based compost and so helps prevent destruction of peat bogs
Composting at home means compostable material (collected in your brown bin) doesn’t need to be transported to bulk composting facilities
It saves money
Why buy it when you can make it yourself?
Compost helps make healthy soil, good soil – healthy plants. Healthy plants – healthy people!
How to compost?
The composting process is simply the breakdown of organic matter by living organisms – bacteria, fungi, worms, insects and other small creatures. Like us they need food, air and water.
Food – this is the material you put in the compost bin (see below – What to compost?)
Air – composting needs plenty of air. You can let air in by turning over the compost with a garden fork but a good mixture of material should make sure there are lots of air spaces in it
Water – but not too much or too little! The right mixture should make sure it’s just right but if it’s too wet then add some more ‘brown’ material or if it’s too dry then add more ‘greens’ or water with a watering can.
Keep adding compostable material bit by bit as it becomes available
What to compost?
Greens and browns 50/50 – not too much of one thing!
Greens – E.g.: grass cuttings, soft green plants, green weeds (e.g. nettles), flowers, raw vegetables and fruit peelings, tea bags, coffee grounds, horse, cattle and poultry manure
‘Greens’ are nitrogen rich; they activate the process but can decay to a smelly mess on their own.
Browns – E.g.: cardboard (e.g. cereal packets, eggs boxes, toilet roll tubes etc.), kitchen roll, scrunched up waste paper, shredded paper, hay, straw, wood shavings, bedding from herbivorous pets (rabbits, hamsters, guinea pigs), fallen leaves, wood ash, hedge trimmings, natural fibres (wool and cotton) ,
‘Browns’ are carbon rich; they balance the process but decay too slowly on their own.
It’s a good idea to put a layer of woody material like twigs or hedge trimmings at the bottom to help air circulate.
What not to compost?
The following must not be put into compost bins as they will attract rats : Meat, fish, all cooked food, bread, cheese, eggshells oil and fat. Also cat litter and dog faeces, coal ash, weeds with seeds, diseased plants and any type of plastic including food wrapping should not be composted.
Where to compost?
You can use a bin or a simple heap on the ground. A bin is easier – keeping your compost neat and manageable. It should have a lid or top to keep heat in and water out
It should be easy to access (near where you grow) in a sunny or partly shaded spot and on soil or grass
How long does it take?
It can take between 12 and 18 months to make mature compost. It depends on the mixture of material and how often you turn it over (turning it over makes sure lots of air gets in, which speeds up the composting).
Check the compost at bottom of the bin – when it’s dark and crumbly with an earthy smell it’s ready to use. Any material from the top layers that hasn’t finished composting can be put back in the bin.
It helps if you have more than one bin so when one is full you can start another – when that’s full the compost from the first should be ready.
Where do I use it?
You can spread it round the bottom of existing plants as a mulch. Dig it into the soil where you are going to plant things or mix it with soil to use as a potting mix to grow your seeds
Useful Resources
Garden Organic: https://www.gardenorganic.org.uk/compost
There is also a short video and more information on the Aberdeen City Council website
https://www.aberdeencity.gov.uk/services/bins-waste-and-recycling/home-composting