Building or buying your compost container is the easy part. Using it to make good quality compost can be a bit trickier. So let’s demystify the compost making process for you……
There are a number of factors to consider, all of which will influence the quality of your compost. On some of them, there’s wide agreement. On others, not so much. Below we’ll talk about a few of those key factors. In a future post we’ll compare the different types of compost container available to you.
Hot, hot, hot!
One of the secrets to good quality (and quick) composting is heat. Good compost relies on decomposers and detritivores. Decomposers are the micro-organisms that help break down waste matter. Detritivores are the invertebrates such as worms, woodlice, slugs and snails that do the same job on a more visible level.
You may have turned a compost heap and felt the heat from the centre – that’s heat produced through the action of those decomposers breaking down the waste matter into compost.
Having a hot compost heap means the composting process is faster, and it also has other advantages. The temperature can kill of plant pathogens and weed seeds that you don’t want to spread when you use your compost on the garden.
What size of compost container you have, where you put it, what you put in it, and what you do with it all help or hinder producing a hot compost heap
What type of compost container?
We’ll cover the range of options in more detail in a future post. It’s often said that a compost heap that’s about 90cm³ to 100cm³ is an ideal size to heat up in the centre quickly and efficiently. Most timber or upcycled pallet heaps are around this size. There are also specialist hot compost containers and tumbling containers which can achieve the same. However these hold smaller quantities of waste.
A container that’s already insulated, or can be insulated will help. The pallet compost container pictured above will lose heat quickly. It would benefit from being lined with a few layers of cardboard before any material is added to it. Bike shops can be a good source of large cardboard boxes perfect for the job!
Siting your compost bin
Opinion varies about where to site compost containers because a lot of other practical considerations come into play. Siting your compost in a sunny spot encourages a hot heap. However, often you’ll be reserving your sunny spots for sun-loving plants or people! Plus too much sun might result in a dry heap, unless you take steps to retain the moisture.
Compost heaps can cope in shadier spots, and you’ll need to think about other things. These might include:
- ease of access to the heap (for adding material, turning the heap, and digging out finished compost for use)
- siting it where it’s less likely to attract rodents
What do you put in your composter?
As you can see from Garden Organic‘s leaflet (left), to get good quality compost it’s important to get the right balance of carbon and nitrogen rich materials in your compost container – approximately half and half.
These are often referred to as Greens (nitrogen rich) and Browns (carbon rich) materials. Too many Greens and your compost is likely to be wet, smelly and slimy. Too many Browns and it’s likely to be dry and poorly composted.
Most advice suggests (as shown right) that you stick to composting plant materials and avoid cooked food, meat and fish etc. That’s not because these items don’t compost. Technically anything that was once alive can be composted.
However cooked foods and/ or raw meat and fish are likely to attract rats. Bones are unlikely to compost in the average domestic compost container. Pet litter may carry disease if your heap doesn’t reach hot enough temperatures to kill off pathogens and so on. So it’s sound advice.
But it’s not as simple as getting the right contents in the right mix, it’s also how you build your compost pile.
Building the heap
The ideal is to build your heap as quickly as possible, if not in one go. In other words collect all your materials to compost and then layer them up. This gives you the size and mix of materials needed to kickstart the decomposers and create a hot compost heap.
Unfortunately, it’s not always as easy as that. You might not have the space to collect the quantities you need. Also some materials shouldn’t be added in large quantities, just as they are. Grass clippings form a dense, slimy mass as they start to decompose, so mix them with some Browns as you add them to the compost container.
Easy as 1,2,3?
There’s also the question of how many containers you need. You may only have space for one. If you can build or afford more, it can help. One container can be ‘cooking’ whilst you’re filling the second. More may be a good idea if you produce a lot of compostable material.
Getting active….
There are any number of compost activators available to buy. I’ve never used them, but know folk who have, to good effect. Others are very critical. There are also more natural, freely available activators, though not all may be to your liking because they include things like urine.
Grow some Russian comfrey – great for the bees, but also good for the compost heap if added in decent quantities. Same with nettles, though avoid adding nettle roots or seedheads unless you’re confident your composter gets hot enough to kill them off.
Turn and turn about
And finally, let’s talk about turning your compost. A well made heap will be hot in the middle after a short time. Give it a few weeks and then turn the compost with a garden fork to mix your Greens and Browns and move the less composted material to the middle so it can ‘cook’.
It’s also a good opportunity to see if you have the balance right and if your heap is moist enough. If it’s dry get the watering can out and dampen it down. And it’s an excellent excuse for a minibeast hunt – marvel at the array of invertebrates at work in your compost container!
