I have to admit it, I’m obsessed with dirt. Not with dirt in the cleanliness-is-next-to-godliness sense but soil. As a grower of edibles I know there’s a direct correlation between what I dig into my pots and beds and the produce on my plate. This obsession with soil is nothing unusual amongst gardeners but for a boutique gardener* like me, it adds a surreal world of smell, colour and scavenging to my life.
Many gardening programmes and books will include information on compost making but how and where do you start if your combined growing space is the size of some of the compost heaps featured in such shows or books, and urban landscapers have stripped any form of soft landscaping from your street?
What and where?
Pallets make great compost bins but are rarely suitable for tiny gardens, balconies and rooftop terraces. I therefore settled for plastic compost bins**, squeezing two into a corner of the garden to be hidden by three foxgloves and a couple of cosmos flowers. If space is even more constrained, it’s possible to make a compost bin out of a dustbin or crate. My friend Wendy (of Rooftop Veg Plot) uses an old wooden trunk with holes drilled in, which she treats as a cross between a compost heap and wormery.***
Air is important to ensure the materials break down so drill extra holes in the container if necessary and regularly turn the contents with a fork. Some people aren’t fond of this job as a compost heap emits different smells depending on the stage of decay. However, regularly turning the compost allows me to keep an eye on its progress – the appearance of thin pinkish worms is an excellent sign – and tweak the ingredients if necessary. It also helps keep rats at bay as they hate changes to their environment.
Heat speeds up the process so placing the compost in the sun is helpful. As many boutique gardens are tiny and sunny spots are prioritised for food or flower growing, siting the bin involves tough decisions. I have accepted that I need to sacrifice some tomato growing space for my two bins but the wholesome compost is definitely worth it. Next year, I’ll try to plant a courgette in one of the bins to maximise the space, nutrients, sun and heat to the full!
Brown and green ingredients
To make compost I scavenge for ingredients from various sources. This may sound like a chore but it’s quite easy as I’ve trained my eyes to see resources rather than waste.
Compost involves a mix of green (nitrogen) and brown (carbon) waste and the balance needs to be broadly right to not end up with a mushy sludge (a sign of too much green waste). I’m not sure what an overly brown mix looks like because a lack of green waste (kitchen scraps, leafy prunings…) is rarely a problem for urban boutique gardeners.
So let’s start with the brown waste. In an ideal world I would add tree prunings and other twiggy matter but as my garden is a fenced patio, these are thin on the ground. Instead I use uncoated paper and cardboard, like egg cartons and toilet roll tubes, ripped into small pieces, and hair clippings (Mr M’s rather than mine as my hair is dyed).
Then there’s the green waste. This comes mostly from the garden itself. Pretty much anything I dig out, prune or clip is an ingredient for the compost heap, although leaves go on a separate pile to make leaf mould. I even add weeds (except bindweed) to the compost bin but steep them in a covered bucket of water till the slurry reeks to the heavens. Technically it’s not necessary to steep annual weeds but I’m too lazy to separate my weeds.
Although I’m a food waste avoider, the kitchen offers some ingredients for the compost as there’s always incidental waste, like vegetable peelings and tops, woody stalks, egg shells, coffee grounds and tea leaves.
Speeding it up
Generally gardening involves patience but as compost is essential for reinvigorating the soil, I like to speed up the process as much as possible.
Heat and aeration definitely help but so do certain chemicals. This word scares many as we automatically think of pharmaceutical products but we all have access to a perfectly natural, free chemical mix that helps activate compost: urine. This may be a step too far for some people but in this boutique garden I occasionally pour a jug of human pee on the compost heap and it works wonders!****
I’ve found another easy, compact system that accelerates the composting process and also increases what food waste we can recycle in situ: Bokashi.
Cooked starches (like bread crumbs and pasta), meat and fish cannot be composted on a regular compost pile as they would attract vermin. A Bokashi bin, however, is a little anaerobic digestion system in which enzymes in special bran (rather than air) fuel the decomposition process.˄ To minimise the amount of air that gets to the waste I collect all our food scraps, including fish bones,˄˄ for two or three days in an old yoghurt tub – which intrigues guests – before adding them to the Bokashi bin with a sprinkling of bran. Once the bin is full, we allow the anaerobic digestion to do its work for at least a fortnight before adding the content to the compost heap. As my kitchen is as boutique as my garden, I store the Bokashi bin into the toilet, once again baffling our house guests!
Emptying the Bokashi bin onto the compost heap is not for the fainthearted. After a couple of weeks the content should have grown lots of fluffy white (rather than green˄) mould and will stink of bile, which makes perfect sense as enzymes are breaking down organic matter. The key is to take a deep breath, decant it quickly, fork it over, cover up the compost heap and just wait for nature to do her bit.
Is it worth it?
Some question whether all this ‘effort’ (i.e. the collecting and mixing of ingredients and waiting patiently) is worth it in a small garden? This year Mr M and I harvested about 300 litres of crumbly, rich, clean smelling, peat-free˄˄˄ compost, which will turbocharge three of our tiny raised beds and several large pots. We’ll definitely need to buy more for growing potatoes and tomatoes but as our beds and pots should supply us with a significant number of our vegetables, converting waste into rich compost is most definitely worth it… even in a boutique garden!
* I’m using the term boutique gardener not to diminish what I and others like me are doing or because our plots are luxurious or pretentious but to distinguish our reality from that of the large ‘small gardens’ featured in mainstream media and to emphasise the skill, imagination, resourcefulness and vision that go into making tiny plots productive and beautiful.
** Many UK councils subsidise compost bins and occasionally wormeries too so do check your council’s websites.
*** Wormeries typically require less space than compost bins so are especially worth considering if space is very tight.
**** Diluted with water (at least 10 parts water) human urine also makes a good liquid feed for plants.
˄ I bought my Bokashi set (two bins and some bran) at a time when my council still subsidised them. Since then, I have bought another 3 kg bag of bran which will last us about two years.
˄˄ I don’t add tea leaves as these are too moist and could cause green mould. Instead I pop them straight into the compost bin. Technically you can add meat bones but if you want to use the compost within a year I wouldn’t as they take longer to break down.
˄˄˄ As peat bogs are important carbon sinks (i.e. efficient natural carbon capture storage systems), peat-free compost is a non-negotiable for me.