Compost is nutrient-rich material that can transform your soil and give plants a dramatic boost. It is created from decomposed organic matter, with help from bacteria, fungus, insects and other organisms.
Making your own compost is an easy, inexpensive and low-maintenance gardening project. Homemade compost is great for the environment too, because it sends less waste to landfill.
Get composting today and produce free plant fertiliser from your own kitchen and garden waste!
Choosing a Compost Bin
Start by choosing the right compost bin for you. You need to consider: how much space you have, how much garden and household waste you have, and what your budget is.
Make sure you pick a suitable spot in the garden for a compost heap. It will need to be somewhere sunny or partially shaded, preferably on a soil or grass base as this will encourage worms which will speed up the composting process.
These traditional bins are square-shaped with no lids. The slatted sides ensure air gets into the compost and the open top makes it easy to turn the compost heap, which can speed up the process.
However, you need to cover the top to keep the rain out, usually with tarpaulin or an old piece of carpet. And the main disadvantage is that you have to leave the entire pile to compost down before you can use any of it. If you have the space, it’s best to have two of these bins together so you have one that’s ready to use and one to add new material to.
Plastic compost bins are usually cylindrical and come with a lid.
The main advantage of these bins is that you can keep adding waste to the top and digging finished compost out of the bottom.
However, plastic bins can be slower to produce good compost because they are smaller and it’s difficult to turn the compost.
You need to ensure the right ratios of material go in.
Many local councils run compost bin schemes, so contact yours to find out if they will supply one for free.
Tumblers are rotating cylinders on a frame that can be turned to effectively mix the compost materials. This can speed up the process to give you finished compost in a much shorter timeframe. Simply fill the tumbler and then turn the drum every day or so for three months to aerate the compost.
However, once the bin is full and the composting process starts, you won’t be able to add to it again. Tumblers are also small-scale composters and lack the added nutrition from worm and insect activity. But they are a good space-saving choice.
Assemble your own wooden bins from pallets or spare wood. Drive fence posts into the ground to make a square and nail boards across the sides. Leave small gaps to allow air to circulate. Make sure the front panel can be removed so you can get the finished compost out.
Make Your Own Compost
It’s important to put in the correct mix of ingredients to get the best quality compost. The finished product should be dark brown in colour, have a crumbly texture and a slightly sweet, damp woodland smell.
You need roughly equal proportions of green and brown waste to avoid ending up with a smelly heap of sludge!
Rich in nitrogen, quick to rot and have a high moisture content.
• Annual weeds and nettles
• Veg peelings and banana skins
• Fruit peel and pulp
• Coffee grounds, tea leaves and bags
• Cut flowers
• Grass clippings
• Soft garden prunings
• Old houseplants/bedding plants
• Rhubarb leaves
• Natural wool/cotton fibres
Rich in carbon, slow to rot and have a good, high fibre content.
• Dry leaves
• Shredded cardboard and paper
• Shredded hedge trimmings and wood chips
• Dead plant stems
• Animal hair
• Wood ash
• Crushed egg shells
• Vacuum cleaner contents
Never Put In
• Meat and fish scraps
• Dairy products
• Coal ash
• Cat litter
• Glossy magazine-type paper
• Weed seeds
How to make Compost
Now you’ve got the bin and the ingredients, it’s time to start making your own compost!
Begin by putting a 10cm layer of coarse material in the bottom of the container to help with air circulation and drainage. This can be twigs and woody prunings, straw or scrunched up cardboard.
Now add equal quantities of green and brown material in 15cm layers.
It is important to alternate because it creates a good balance for the composting process, and reduces the need to turn the compost.
You can also add a sprinkling of existing garden soil on top of each layer – this will add the vital bacteria and fungus to start the breakdown.
For the fastest results, fill the entire compost bin at once. A large pile will speed things up because it has enough mass to generate heat and decompose everything. If you add a little material at a time, it will take longer to heat up and produce compost.
If you’re lucky enough to have the space for two compost heaps, you can start a second one to continue adding waste to, and use the matured compost from the first.
If you want to fill the bin gradually, follow a simple rule: every time you add green material, add some brown too. This will create air pockets to speed up composting and stop the mixture from becoming too wet and slimy.
Cover the compost to keep out rain and stop it getting slimy. Turn it over once a month to aerate it and speed up the process. Use a garden fork to mix the outer contents towards the centre.
Eventually, you can decide to stop adding ingredients and leave the heap to mature.
Or with a plastic bin, you can start to use the lower layers which have finished composting.
Compost is ready to use when it is deep brown, crumbly and sweet-smelling. If it still smells rotten, it’s not ready.
It’s too wet/dry
Too little moisture will slow down the composting process, and too much will turn it into a slimy mess. To check the moisture levels, turn it over with a fork. It should look damp all the way through.
If it looks dry, add some water and turn again to mix. Check again in a week. If it looks wet, keep covered from rain, turn regularly to aerate and add more dry materials like straw, sawdust or shredded cardboard.
Save the endless trips to the compost bin with a kitchen composter to collect your fruit and veg scraps as you go.
It’s not composting!
If your compost is woody and not breaking down, try adding more green materials like grass clippings. You can also buy a compost activator to add that extra bit of nitrogen.
It’s attracting lots of fruit flies!
Fruit flies don’t cause any harm but they can be a nuisance. Get rid of them by covering the compost bin with a lid and burying any fruit and veg scraps, rather than just tipping them on top.