My Compost Heap Frightens Me

At the end of the garden lurks an oozing, pulsing heap of darkness.

I try to ignore it. I smile at the innocent little daisies on the lawn, admire the pretty ladybirds, glory in the swifts overhead and am grateful for the beauty all around. But the horrible truth cannot be denied: Decay resides in a far corner. Busy Decay at that.

Edgar Allan Poe missed a trick by not making a compost heap the menacing centre of a short story. Like the portrait in the attic, or the maddening beat of a heart, the compost bin sits, doom laden, forever warning of the end that awaits us all.

I suppose you've got to get to grips with this reality if you are a gardener - a thoughtful, ecologically aware, bit of a depressive kind of gardener anyway. The cycle of life and all that. You put dead plants in, let an Hieronymus Bosch horde of creatures eat it up, then eventually get life-giving compost out at the end. Grim.

 

A Yellow Slug, Limax flavus (Lt flavus = yellow)

White-lipped Snail, Cepaea hortensis (Lt hortensis = garden)

Muck Raking With Sally

So, Eric delivered.

Unfortunately I missed him, but that's OK because Sally said he wasn't a lithe Pole. And although he wasn't wearing a flat-cap, he did sport a fine set of dentures.

But seriously ... the compost comes from a social enterprise company, Fairfield, that is situated on New Smithfield market site in East Manchester. They use the waste fruit and veg from their neighbours and woodier waste from the council or landscapers to produce an affordable compost with a low carbon foot print.

Here is a neat view of the composting process.

The stuff that Eric brought was quite woody, and he advised us not to plant directly into it, so it is certainly not suitable for planting up pots, but the soil on Allotment90 has a high clay content and will benefit from the increased texture and carbon from bits of chopped up stick.

We spent an hour and half spreading half of the compost on the ground we have so far managed to weed, and the rest we put in a storage area.

It is good to see the allotment looking neat and tidy and vibrant.

And here is proof that when the occasion demands I can wield a shovel like a pro:


Naturally, after our heroic effort we retired to the nearest cafe and scoffed down a Danish (pastry).

Micro Organisms In The Compost Bin

In the last post micro organisms took centre stage. These are the single-celled little guys who are going to eat up all those banana skins and pizza boxes to make nutritious humus for my roses. What heroes. But how are they going to do that and how long will it take, and who are they?

The vast majority are bacteria. Most are the kind you wouldn’t want to meet on a dark night, but some are responsible for the antibiotics we use to fight illnesses like TB. Bacteria will eat anything, living or dead. The general idea is that they will break down matter to use the carbon and nitrogen and in doing so release gases like CO2, generate heat, and finally leave organic matter that can be used by plants.

There are three types of bacteria that get to work at different times in a compost bin:

• Psychrophilic – appear when the compost is new and cold. They prefer temperatures between 10 and 21C.
• Mesophilic – are dominant when the internal temperature rises to 21 - 38C. If there is not enough nitrogen or oxygen the compost will stay at this phase and will not develop further, so the pile needs to be turned to give these bacteria plenty of food.
• Thermophilic – appear when the compost gets hot. It’s only after the temperature reaches about 70C or they run out of carbon that the population declines.

It is surprising how quickly the temperature inside the bin rises. The earlier cooler phases last only a few days. By breaking down the sugars and starches that are easy to get to the early bacteria populations raise the temperature enough for the thermophilic bacteria to grow. It is during this hot phase when dangerous pathogens get killed off and more difficult cellulose rich material is broken down. After this intense phase, which could last days or months, a longer more sedate period starts where the work really begins. I imagine this is when they creepy crawlies and worms do their stuff.

I’ve just stuck a cooking thermometer (normally used by my son to temper his chocolate – that’s another story) into my compost bin. It’s 26C, which means it’s still in the mesophilic stage. Super. The little guys are starting to do their thing, but the big boys haven’t arrived yet. (And yes, mum, I did clean the thermometer after)

I hope this little exposition hasn’t been too boring. Bear with me, it’s just that I’m a little in love with my compost bin at the moment and I want to know ALL about him.

Why Newspaper Is Added To Compost

So why am I adding newspaper to the compost bin? Let me explain the apparent madness.

The dream behind the composting effort is that the veg. peelings and shrub prunings are going to be eaten by micro organisms who after their gluttonous orgy will leave behind a nutrient rich humus I will use to mulch my Albertine rose, that in turn will then cover the fence in a beautiful luxuriant mass of flowers.

OK, so we’d better provide the right environment and food stuffs (think oysters, champagne and mood lighting) to encourage the micro organisms to do their thing quickly and efficiently. If we leave the environmental factors (temperature, water, etc) to one side, and look at the material they will consume it becomes apparent an optimum amount of carbon and nitrogen is needed. Carbon is used for energy, and nitrogen to build cell structure. As these organisms live for only 20 minutes or so a lot of carbon and nitrogen rich vegetable matter needs to be provided to fuel the many generations it will take to turn twigs and egg shells into useable compost.

A balance of both elements within the compost bin needs to be maintained. Too much carbon slows the process down because the organisms don’t have enough nitrogen to complete the process of decomposition, and alternatively if there is a surfeit of nitrogen it will escape the bin as a gas, nitrous oxide, a foul smelling waste of the very nutrient you are trying to capture for your plants. People who study these things say a ratio of about 30 parts carbon to 1 of nitrogen is the right mix to enable efficient decomposition. This ratio is generally written as 30:1.

Having learnt that lets look at what we are putting in the compost bin to see if it fits that ratio.

Composting people divide the waste put in compost bins into ‘green’ and ‘brown’ material. Green has more nitrogen in it than brown material. For example, kitchen waste with a ratio of 25:1 has more nitrogen in it than shredded newspaper at 175:1. As it’s usually the green kind of waste that gets added to compost bins some brown stuff needs to be included to up the carbon content. Adding newspaper or cardboard has an added benefit in that green material tends to be fine-textured and moist. If that is all there is in the bin you will end up with a bad smelling sludge, so layering it with dry cardboard opens up the texture (so those micro organisms can breathe) and dries the mixture a little.

The advice scientists and Mr McGregors the world over give is each time you put something in the bin use 50% green and 50% brown material, eg, a bucket of weeds and a bucket of dry leaves.

So this is what I am trying to do with my brand new compost.

However, I’ve no idea if I’m doing it right. I’m throwing in pizza boxes and shredded Guardians, but goodness knows if that is the same volume of green stuff. It’s really a matter of ‘does it look like the pictures in the composting books borrowed from the library?’. No actual measuring is involved.

Apparently you can roughly calculate your C:N ratio by adding up the various ratios of the waste you’ve chucked in then dividing by the number of units. For instance if you added equal parts of kitchen waste, grass clippings and leaves you get this neat formula which ends in a good enough ratio of 34:1:

25:1 + 17:1 + 60:1 = 102:3 = 34:1

Now let’s look at an estimation of my mix. ‘Some weeds and a couple of boxes’ give a ratio of 102:1.

20: 1 + 20:1 + 20:1 + 350:1 = 410:4 = 102:1

Hmm.

Lots Of Compost Bins

I got a text from Sally this morning. She had been given the key to the magic kingdom and would I like to join her? Of course! So abandoning all domestic duties we snuck in - and what a wonderful place it was full of ruby red raspberries, crispy skinned onions, giant cardoons, sunny nasturtiums, and most excitingly of all: - compost bins!

In reality Sally had the key to our local allotments in Didsbury because friends of hers, who have a plot there, are away on holiday and have asked her to pick their raspberries. These allotments are behind a thick hedge and a padlocked gate, so I’ve never seen them. It’s like a whole new world in there where people committed to vegetables have created an ordered and beautiful space. The purpose of my visit was to see how proper gardeners create compost bins, but I have come away inspired to spend more time on the garden as a whole. I have to say that having been to open gardens and an RHS flower show this summer it is these allotments that have impressed me the most. Now there is a little voice in my head saying, ‘You want this too, don’t you? Admit it, go on’.

Worryingly not one of these piles has newspaper and cardboard in it.

But I'm glad to see pallets being used to construct the bins.

Some looked like World War 1 rampart walls.

Plastic darlek-like bins were also being used.

And some people had professional two bin systems.

With roofs.

Nearly all were covered. I'll have to find a bit of old carpet.

Composting Begins

Let the show commence. 

As Anna imaginatively observed the new and empty compost bin looked like a stage set ready for a magic show to start.

With some first night nerves the players have now begun to assemble. The boards they are treading on are made of black bamboo sticks. This foundation layer is there to allow air to circulate and be open enough to let earthworms come up from the stalls and participate in the whole composting event.

I think we can visualise this first act of the show as of similar epic scope as the beginning of the Olympic opening ceremony. So here we have a general accumulation of earthy peasants pleasantly going about their bucolic lives. First a layer of old weeds appears accompanied by a sobering mix of torn newspaper. Then the excitement increases when the first mound of kitchen waste enters stage right. This adds a colourful, fruity tone to the show that the fruit flies (who have been queuing round the corner all night to be sure of the cheap seats) particularly appreciate. Lastly a generous mound of jasmine clippings swarms onto the set. Although their sweet nitrogenous nature is tempered with cardboard from pizza boxes the stage manager worries the jasmine will start saying their lines too quickly and will end up in a mushy mess of incoherence.

 So we haven’t yet got to the part of the show where Kenneth Branagh turns up in a top hat - the assembling of green peasants will run for a few more weeks - but all in all it looks a good beginning.

And the critics seem to be favourable

 

I Make A Compost Bin

Here is my lovely new compost bin.

No longer will there be awkward silences when someone asks 'do you compost?' Not only can I reply 'absolutely!', but I can proudly add 'and I made it myself'. 

The back is a pallet robbed from a neighbour's skip (shh), and the sides are old fence panels. A trench was dug to sit them in, and the panels are packed with bricks to keep them steady. A trick remembered from my previous life as an archaeologist: the central poles of Iron Age roundhouses were packed with stones. Don't know if it will work but if it's good enough for the ancients...

The bin is bigger than planned. To be honest I'm not sure it will ever get filled. In one way it will be a shame if it did. The space inside it, in it's clean unused state, is lovely and cosy like a den. The turned earth smells lovely and if you crouch inside no one can see you. It's a secret place that makes me want to raid the kitchen for a pork pie and bottle of ginger beer, and spend the afternoon reading a book about horsey girls going to gymkhanas.

What's In The Bin?

Were you aware it is National Compost Awareness Week?

It ends tomorrow, so don’t worry you can return to blissful unawareness next week.

For me however this is eerily fortuitous since now there is a patch of bare earth at the back of Garden 65 there is room for a compost bin. I had a shuffle round the internet on the subject of composting which led organically (geddit?) on to looking more closely at the food we throw out.

There is an organisation supported by Defra called ‘Wrap’ which is involved with researching and educating people on reducing waste and ‘minimising resource use’. They are interested in the whole spectrum of recycling from plastic bottles to textiles, and speak to industry as well as the general public. I am impressed with the thoroughness they take the issue.

We are used to politicians, assorted eco-people, and self-righteous friends preaching about saving the planet by reducing our carbon footprint, not putting old clothes in the bin, and well ... composting, but these messages come heavy with an emotive and moral undertone – or so it seems to me. The implication is that ‘good’ people recycle and that is the only reason you need to do these actions. I consider myself a generally ‘good’ person; I care very much for unspoilt nature, and the fact there are ever decreasing resources for an ever increasing population. So I comply with the recycle message and diligently put milk cartons in the blue bin and milk bottles in the brown bin (think that’s the right way round). How much of the motive for my good deeds, then, is really the human need to feel as if I am doing the right thing; that I’m on the winning side? It is primarily, I have to admit, an emotional decision barely based on any firm scientific facts. And I would suggest many people, of varied political persuasions, are doing just the same.

Which brings me back to compost awareness week, and Wrap. Amongst the research they have done is a fascinating (no, really!) 95 page report on ‘Household Food and Drink Waste’ which reveals the type of food we throw away, why we do, and by what route (1.8 million tonnes is chucked down the sink). I’m a good girl so I scrape peelings and leftovers into the neat kitchen top bin that then goes in the green bin that then gets emptied into the big lorry that then ... I don’t know what happens next but I trust the council do something wise with it. But what about the beginning of that cycle – what about the food waste itself? Without a twinge of regret or guilt unwanted food gets thrown away.

Reading this report made me think about the food wasted in Kitchen 65. According to the report over 60% of food and drink waste is avoidable. By this they mean that which is no longer wanted or has been allowed to go past its best, but was once edible. Non avoidable, always inedible, food takes up less than 20% of the total weight thrown. Just for the fun and geekiness of it I took a snap shot of the food in the little bin on the kitchen top to see if these figures were reflected in my world.

Contents

End of lettuce
Banana skin
Carrot peelings
Tea bags
End of cucumber
Bread crusts
End of loaf
Tomato stalk
Coffee grounds

This weighed 526g in all. Half a kilo even before the main evening meal had appeared!

The unavoidable items were the banana skin, tea bags, tomato stalk and coffee grounds. These added up to 240g. I’m no mathematician but that’s about 50% unavoidable, or half avoidable – roughly the national average. I suppose you could make bread and butter pudding with the end of the loaf and the crusts, but I’m not sure what creative thing you could do with the pointy bit of a cucumber (one of those healthy green smoothies?).


Obviously this is just a bit of fun and not properly representative, but it was an interesting exercise to look closely at my actions as I live this privileged Western life.


Like the majority of people I don’t know for certain how I could help ‘save the planet’. What are the numbers? Where are the undisputed facts? As a normal invisible suburban person all I want to do is tread lightly on this earth (as the Buddhists advice). That is enough motivation for me.


As for the compost bin ... seems bit of a faff.