A Guide to Composting & Composters

Composting is so easy peasy it’s a shame that more people don’t do it. It can also save you a fortune in waste charges and in garden compost. It’s also the only zero-waste way to get peat-free compost. It’s also the only way to get compost with no nasties in it. Did you know that organic compost only needs to be 51% organic to use the term? This means that certified organic compost can contain material sprayed with weedkiller and insecticides, and seeing as it can take 2-5 years for these chemicals to become inactive you may inadvertently end up putting harmful chemicals into your garden.

I did hear reference to a research paper that found evidence of methane being created by home composters. Methane is said to be 7-30 times (studies differ) more damaging than carbon dioxide when it comes to climate change, so this is a big concern.  I tried to get access to this research paper but I’d have to pay for it. If I do i’ll update this article. For now i’m going to work off my existing knowledge, which is that methane is only created when biodegradable material decomposes in an anaerobic environment, i.e. an environment devoid of oxygen. So the best way to avoid generating methane is to make sure you’re composter is well aerated, which may well influence the type of composter that you buy or make.

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How to Compost
Regardless of the style of composter you opt for here are a few simple rules on what to put into it.

• no cooked food*
• no dairy, including egg shells*
• no meat*
• no perennial weeks, like dandelions or bindweed. If in doubt leave it out or you’ll be spreading weeds all over your garden.
• alternate dead material (brown) – twigs, leaves, newspaper with fresh material (green) – vegetation from the garden, uncooked vegetable & fruit scraps from the kitchen. I keep a bag of dry leaves or shredded paper beside the composter to add in between layer of kitchen scraps / garden waste.

There have been some concern over putting coffee grounds into compost bins. Put directly on the soil coffee grounds have been shown to inhibit the growth of plants and earthworms die in compost heaps with coffee grounds. They also compact too quickly to be used as a mulch but given their detrimental effect on plant growth they may work as a weedkiller.

* some compost bins say that they can take these items. I don’t have one so can’t verify this claim.

Some Tips for Composting
In my experience the smaller the compost bin the finer the stuff needs to be. When we had a compost cone the stuff had to be quite fine but now that we’ve 1.5m x 1.5m, bins we’re getting away with not having to shred or break stuff down at all. That said the finer the material you add to the compost heap the quicker it’ll decompose.

A compost bin needs oxygen to work. If the heap gets compacted then no air can circulate and the bacteria that breaks the material down into compost will die off giving off a foul stench and halting the composting process. If you’re worried this is happening turn your compost to add in oxygen.

The hotter your compost bin the quicker the materials will compost. In my opinion it’s a fine balance between temperature and air flow and personally I’d rather have great compost over a longer period than risk anaerobic (no-oxygen) hot mess by insulating too much. We don’t bother insulating our compost bins and so they take about 1 year to break down 80% off what’s put in them. If you want to speed-up the composting process then consider getting a thermal compost bin (see below).

You need at least two sections / bins. In my experience the hatch at the bottom of compost bins it completely useless for removing composted material. So we have two bins and when we’ve filled up one we cover it with some timber and start on the second one. We’ve big bins (1.5m x 1.5m) so it typically takes us a year to fill each one. This means that when one is full it’s about time to take the compost out of the other one, and then the process starts all over again. If you have a third bay you can use this to rotate your compost thereby speeding up the composting process.

If you really want to geek out on the value of composting for nature this is a great downloadable guide from An Taisce

Types of Composters
Before I launch into a list of the various options for compost bins I would like to clarify that having one is not essential. If you want you can just toss your green waste and brown waste in a corner of your garden and it’ll work away fine. If you don’t fancy doing that and would like to invest in a compost bin then here’s an overview of the types on the market.

Rotating Composters / Compost Tumblers – These are great because they’re resistant to attack from rodents, take up very little space and allow for easy rotating of composting materials, which results in faster composting.

At the top of the list is the Big Pig by Joraform at a whopping €495 (see pic above). The makers of this 270 litre compost bin claims to turn waste into compost in as little as 6-8 weeks and says that it can take cooked meat and fish waste.  You can also get a 200L rotating composter for €110 from Fruit Hill Farm or for €100 from a Co-op Superstores, although neither have two compartments like the Joraform models so you may want two.

There’s also this very fun rollable composter by Composhere, which is made from recycled plastic and holds 315 litres. It’s a very reasonably priced £101 but as it only has one compartment you’ll also need two of them.

Or you could make your own rotating composter from two upcycled drums.

Timber Compost Bins – A timber compost bin would be by far my preferred choice as the material used to make it is in itself compostable, once it’s not pressure treated! A timber compost bin can be homemade from heat treated wooden pallets or untreated deck boards or be a proprietary one like this Timber Compost Bin from Quickcrop for €119 or these from Original Organics.

We were delighted to find a well-priced timber compost bin made from Irish grown larch, which doesn’t need any chemical treatments. It doesn’t come with a lid, but that suits us fine as we never used one.

Some compost bin have removable bottom sections to help you get to the composted material. In my experience these don’t work, as you can only really get to the front of the composted material. What’s better is if you can remove the whole front of the compost bin.

The one we bought above doesn’t have this feature. Instead you take off the timber sections row by row. Hopefully this won’t be an issue as we intend to empty the compost bins all in one go in spring, when we spread the compost on our beds. I’ll update this article after we’ve done that.

If you’re compost bin is going to be on show then perhaps an uber-cute timber beehive bin will tickle your fancy. This version is made in Ireland and comes with removable sections to help with compost removal.

Compost Cones – This tends to be the iconic form for compost bins in Ireland and England primarily because they’re the cheapest kind to buy. I really don’t like these bins and I think they’re the main reason people give up on composting. We used these in our previous garden and we found it very hard to ensure enough air got to the compost, although this can be helped by drilling holes in the side of the cone. As I’ve said above the little hatch at the bottom is completely useless for extracting compost and we also found that the only way to rotate the compost was to tip the entire contents out onto the ground and put it back in. A nasty job indeed! Quickcrop has a compost cone with air vents at the bottom and a larger than average bottom opening but personally I’d still recommend a square or rectangular timber compost bin over a compost cone any day.

Thermal Composters – Although it looks like a traditional compost cone the Green Johanna Composter is designed to retain heat in the compost head thus speeding up the composting process. You can even purchase a special lagging jacket for it to keep temperatures up during the winter. The Green Johanna is said to be able to take cooked food, meat, dairy, bones and fish. Another model on the market is the Thermostar Composter Maker, which is made from foamed HDPE (plastic) which traps bubbles of air in the plastic offering greater insulation than non-foamed plastic. It cannot take cooked food, meat, dairy, bones and fish.

Another brand of thermal composter that can take meat, cooked food and bones is Hotbin Composting, which won product of the year at the Chelsea Flower Show in 2019. This wheely bin-sized unit claims to create compost in 30-90 days. There are two supplier in Ireland for them, which you’ve find listed on this webpage.

The other option is to make your own composter. Lovely Greens has a very good tutorial, with video, on building a homemade compost bin from pallets.

Composting Inside
If you don’t have a garden you can still compost either using a wormery or the Food Cycler. Wormeries can take cooked and raw food but the worms don’t like food waste that’s too acidic so you need to be careful about adding citrus fruits, garlic and onions to it. It’s also suggested that you avoid adding fish waste as this can cause a smell. You can located wormeries outdoors but the worms are much happier in a warm house / apartment than outside and will work much more effectively as a result. Wormeries come in a variety of sizes from counter-top stainless steel versions to floor mounted models. You can even get a wormery that doubles as a stool. You can read more about how wormeries work here. You can buy wormeries and worms for a wormery from Kerry based The Worm Bin.

The Food Cycler is a counter top unit that heats up and agitates food causing it to decompose over a very short space of time (3-4 hours). It can take cooked food, meat, dairy, fish and chicken and fish bones. A review on Amazon, said that they’d buy it again even though they found 1) the unit noisy, 2) some recognisable food bits at the end of the process, which might attract rodents if used directly in the garden, 3) and that waste entered must be balanced to avoid a sticky mess. Also one wonders if using electricity to break down food waste is the most sustainable option plus the fact that the unit needs replaceable filters.

Food Digesters
Unless you have bought a composter design to take cooked food, meat, dairy or fish you’re going to have to handle this waste separately from your uncooked fruit and veg waste. This is where digesters come in.  Digesters process food waste so that it’s easier to dispose of it, by either burying it or adding it to your traditional compost heap.

The Green Cone Food Digester uses solar energy to break down food waste such as vegetable scraps, raw and cooked meat or fish, bones, dairy products and other organic kitchen waste e.g. tea bags, bread etc. According to the manufacturer the unit utilises solar to create heat between the inner and outer layers of the cone, thus promoting air circulation, and converting food waste into water, carbon dioxide and small amount of residue that only needs to be removed every few years. I haven’t used one of these so can’t verify these claims.

Another option is a digester that captures methane emanating from the decomposting waste, which you can use to power your gas applicances. One such device is the MyGug, which you can buy directly from their website.

Bokashi bins are often used by people to process cooked food waste indoors. The name ‘bokashi’ is Japanese for ‘fermenting organic matter’ and the system uses a bran-based material that has been activated with micro-organisms (friendly bacteria) and molasses. I’m told that the process doesn’t (shouldn’t) produce any odours and that it is capable of handling cooked and uncooked food including meat, fish, fruit and vegetables. Once the food waste is suitably fermented you are meant to dig it into your soil or put it on your compost bin. The model shown above is called the Urban Composter and is the most stylish bokashi bin I found. You can read more about Bokashi Bins here and here’s some direct experience from a Bokashi user. There’s also a FB group for Bokashi Bin users.

Keeping Rodents out of your Compost Bins
One of the main concerns with compost bins is the possibility of them attracting rodents. We have a stream and a line of houses running along the back of our house and you can bet your dollar that there are rodents in that area. Having grown up in the countryside I’m very use to wildlife being outside my back door this doesn’t bother me in the slightest. I don’t know if our compost heap has been visited by rodents but it’s at the bottom of our garden so over the past 8 years it hasn’t been a problem. They’re probably more likely that they’d visit my neighbours who chuck stale bread out on their back lawn! If you’d like to minimise the risk of rodents then try the following;

• Buy a sealed compost bin
• Sprinkle chilli powder on the compost heap
• Sprinkle Peppermint oil on the compost heap
• Place some ferret droppings near the heap
• Put a sturdy lid on the compost bin and lay some chicken wire under and around the heap

Our Compost Bins
My approach to life is to get maximum output for minimum input and composting is no different. We don’t insulate our compost heap, we don’t cover it and we don’t protect it from rodents and for the past 15 years it’s been working a charm. We have two 1.5m x 1.5m bins that we fill with un-shredded garden waste and uncooked fruit and veg peelings (green material). We keep a bag of dry leaves, collected in Autumn, or shredded paper near the compost heap to use as the brown material in between the green material. Once a bin is full we cover it with some timber, only because we have it, and start filling up the second bin. We don’t use an accelerator and it takes approximately 1 year for the material in one bin to compost once it’s full.

The compost bins we have are made from pressure treated timber boards and galvanised metal formed corners. We bought the timber boards from a builders merchants and the corners came from French company Jardin Eco, but unfortunately it doesn’t look like they sell them anymore. I picked this because I liked the overall look of the finished unit and that we could use my own timber boards.

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