What exactly is compost?

It’s essentially organic matter that’s reached a certain level of decay. As well as being a rich source of nutrients, it’s packed full of microscopic bacteria and fungi. These make it easier for plants to absorb what they need in order to flourish.

Compost also improves the texture of soil – making clay soil lighter and giving sandy soil more body. It thus becomes more crumbly and easier to handle, as well as being better equipped to retain moisture.

Reasons to make your own compost

  1. It’s expensive to buy. If you’re growing organic vegetables, you won’t want to use anything that’s been treated with chemical fertilisers. If you’re a strict vegan, you won’t want to use anything made from animal products either. Compost that’s both organic and from purely plant-based sources is especially expensive, and can be difficult to find, but we can highly recommend Vegro, by Fertile Fibre.
  2. Composting is a great way to recycle household waste. If you’re on a plant-based diet, you’re going to be getting through a lot of fresh vegetables and fruit. This creates a lot of spare goodness that could be turned into ‘black gold’ as it’s called amongst gardeners.
  3. The compost bin is perfect for recycling waste from a vegetable garden too. When you grow your own food, you’ll end up with a certain amount of inedible plant matter – roots, stems, yellowing leaves – that will nonetheless be packed with nutrients. Composting is a way to use pretty much the whole plant, apart from the toughest of stalks.

Where to start?

Daunted? Don’t be. If I can do this, almost anyone can. I’m not exactly built like Giant Haystacks. I also grew up with an almost pathological fear of getting my hands dirty, and a pretty severe aversion to worms, so the odds of me getting into this were next to none.

Now I know how useful compost can be and what an amazing process it is, I’ve grown into a bit of a compost-nerd. Admittedly you need a basic amount of physical fitness to keep the process going, but there are ways to keep the heavy work to a minimum.

It needn’t be complicated either. If you were to dump a load of vegetable peelings in a corner of the garden somewhere, it would eventually turn to compost of sorts. To speed up the process, and to make it more hygienic, you’ll probably want a container. There are a few other things you can do to ensure quality results, and to make it all manageable.

Firstly, it’s best to wear gloves when handling compost – not all of its bacteria is good 🙂

What sort of bin to use?

  • Go for a decent-sized bin if you have the space for it. The more you can compost at once, the quicker the material will break down. A bin of around 500 litres is good for two people who eat a lot of fresh stuff, and perhaps grow a few things at home. It’s good to have a smaller backup bin as well if you can find room. If you have plenty of space, perhaps consider going for 3 bins of equal size – that way you can be filling one bin while the others are at different stages of maturity. This cuts down on some of the work.
  • A bin should be sturdy. The weight of the contents will put considerable pressure on its walls.
  • It should have some kind of secure lid or cover. You want the pile to be able to breathe and have a bit of moisture, but it shouldn’t get water-logged. Too much water will cool the pile down, and will also reduce aeration.
  • It should have a big enough opening. You’ll want to have easy access when you’re throwing things in, so make sure the lid opens wide, and is easy to manage – preferably with one hand.
  • Ideally, make sure the walls have some insulation. The composting process generates its own heat, which in turn helps with the decomposition. Wood is a good material, or if you go for plastic, look for double-walled options.
  • Air holes are not necessary. It’s better to aim for aeration throughout the pile, rather than just at the sides.
  • Trap doors can be a nuisance. Some containers have little flaps at the bottom, allowing you to scoop out small amounts of compost. The idea is that you keep filling from the top and taking out from the bottom – a noble sentiment, but we’ve not found it very practical. Due to the weight of material above, you’ll never be able to get into all the corners below – at least not without causing an avalanche – so there will be a lot of wasted material and quite some confusion in the layers of your pile. The other problem we’ve found is that the doors are forced open by the weight above, and it’s a job to fight them closed again. We just wedge ours shut with bricks, but would probably rather they weren’t there at all.

A note on sizes: the quoted capacity of bins seems to vary – it can be anywhere from 60 to 100% of the actual volume. Check the dimensions before buying – not just to make sure you have space for the bin’s footprint, but also to know how much actual volume you’re getting. We tend to fill ours pretty much to the brim, so we go by 100%. (If, like me, your maths is not great, you need to multiply the height x width x depth in centimetres, then divide by 1000 to get the litre capacity).

Choosing a location

Obviously you don’t want a compost bin too near the house – they attract flies in the summer and can be rather less than fragrant close-up. On the other hand, you don’t want it so far down the garden that you end up making excuses. Ideally, put it close to other waste bins, so you can just add to it as part of your daily rubbish routine. Keeping a caddie in the kitchen is an easy and hygienic way to collect waste indoors. We use this neat little one from Addis.

The bin needs to be on level ground with decent drainage.

Place it on bare soil, rather than on a paved area, so the worms can access it.

It should be easy for human access too – not just for adding waste, but also for maintenance and decanting. Ideally you’d be able to get a wheelbarrow right up to it.

Putting it in a sunny or partially sunny position will help to keep its core temperature up.

Tomato leaves

What (and what not) to compost

Aim for a healthy mix of ‘green’ and ‘brown’ material – roughly 50-50 in volume. Greens are rich in nitrogen, whereas browns contribute carbon. If you think of the bin as a digestive system, nitrogen is the nourishment, and carbon is the fibre.

Brown material helps to keep everything aerated. As the micro-organisms feed on oxygen, this is important in speeding up decomposition. Brown material also helps prevent the pile from developing unhelpful mould.

Below are some plant-based examples of each:


  • Raw fruit & vegetable waste (including citrus, contrary to popular belief)
  • Tea leaves & coffee grounds


  • Straw & hay
  • Stems & roots of vegetables

Don’t compost:

  • Cooked food or fats (these attract pests)
  • Fruit stones (from peaches, avocado, plum etc)
  • Anything diseased
  • Weeds (at least not their roots, flowers or seed heads)
  • Tomatoes or anything else that might germinate when you don’t want it to (the photo above shows how we know this 🙂 )

Do or don’t?

  • Teabags – they usually contain a small amount of polypropylene, which is not biodegradable. This is set to change soon, as even big producers are addressing the issue. It’s generally a problem for sealed bags. String-and-tag bags usually don’t have plastic, as a seal is not needed – just throw out the string and tag, as they’ll take longer to break down. Some teabags are bleached, so that’s another thing to consider.
  • Cut grass – use it fresh as ‘green’ matter only in moderation. It’ll be high in nitrogen, but it tends to turn slimy. If you want strictly organic material, make sure the lawn’s not treated with chemicals. Some say even non-organic should be safe for vegetable gardens after a few months, but that’s for the individual to decide. The best way to compost grass cuttings is to dry them out first – this counts as ‘brown’ material, though it’s still also high in nitrogen. Ideally spread them out in the sun until they turn dark grey-green. If the weather’s not great, they can also be laid out in a well-ventilated place like a shed for a couple of days. They’ll turn yellowish, and won’t be quite as dry, but will still be full of goodness. Worms absolutely love grass cuttings.
  • Brown paper or cardboard – it’s fine to include a moderate amount as ‘brown’ waste, but make sure it doesn’t have a plastic coating. Just tear and scrunch it up a bit to help make little air pockets. Avoid white paper, coloured paper, or newspaper as it will contain a lot more chemicals. Even brown will usually have a small amount of bleach.

Want to get your hands on ‘black gold’ sooner? Learn about accelerators and aerators in How to speed up composting. Also check out our 12-month plan for maximising use of your bin.

Got any tips or questions of your own about organic plant-based composting? Leave us a comment below, we’d love to hear from you.


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