A compost heap is a wonderful thing, converting organic rubbish into dark, moist, humus-filled garden fertiliser. Every serious gardener needs a compost heap and even the not-so-serious can enjoy watching the wonderful process of turning household rubbish into sacks of moist, black, fragrant compost.
Fragrant? Have you ever smelled a woodland waking up after a night's sleep? The smell of damp earth after rain; the smell of bluebells growing and butterflies feeding? That's what good compost smells like.
I think it is awesome, seeing a cold compost heap converting all kinds of blackened vegetables, slimy cucumbers and cold tea leaves into this rich, nutrient-filled fibre. It takes a few months, but set the heap up right and you can leave it alone, quietly performing one of nature's greatest miracles in a dark corner of your yard. A season or two later, the heap is crumbly, moist compost, filled with worms and centipedes; bacteria and fibre. Just right to feed a new generation of plants, helping them grow strong in the new year's sunshine.
You don't need a huge heap, nor do you need to keep it topped up with barrow-loads of vegetable matter. That's a hot compost heap, and those are only for the professionals, or near-professionals. A hot compost heap needs looking after; it needs feeding, changing and checking every few days. Hot heaps are wonderful because they do the job quickly, in weeks rather than months, and the heat kills seeds and disease-causing bacteria, making it safer to use on the garden.
A cold compost just sits quietly in the corner, minding its own business, feeding its host of industrious residents and slowly converting rotting cabbage and broken roses into a gardener's black gold. It generates a bit of warmth, but not much. Just enough to give the worms a peaceful home, slightly warmer than the cold winter air.
What's so special about compost?
It's all but impossible to reduce this miracle of nature to words like fibre and soil enrichment and nutrients. I'll try for a moment and say that garden compost makes poor soil better and turns good soil into the kind of environment where plants can't stop themselves from growing and flourishing.
Adding good compost to soil is like bringing great food, kegs of beer and the very best possible music to a slow party. It allows the plants to flourish and everyone to enjoy themselves.
Compost changes a thin, dry soil into one that can hold water and store nutrients. It softens heavy soil allowing water to drain, providing space for creatures to grow and nutrients to feed them. In every soil it improves drainage, adds food, improves the texture and helps plants absorb the nutrients it brings.
And it smells good and feels good to crumble it in your hands. It's soft, moist, welcoming. It smells like damp woodlands and growing things.
How to make a good compost heap
I'm no professional gardener. I don't keep hot heaps, so I'm going to tell you about that everyday little miracle of garden lore: the cold heap. If you have to know about hot heaps, then you need to know about balancing green stuff like grass, with brown stuff like twigs and leaves. One book I have says green is nitrogen and brown is carbon, and you have to layer the two. I'm not sure about the carbon/nitrogen thing, but a hot heap needs alternate layers of green and brown to make sure the green stuff doesn't consume all the oxygen and start the gross, smelly process of anaerobic decomposition. If you loosen the heap once or twice a week with a fork, to allow more oxygen into the heart of the heap, it should be enough to keep the thing breathing oxygen. It's when the heap runs out of oxygen that the smelly anaerobic processes take over.
With cold heaps, you don't have to worry so much about layers and anaerobic bacteria. You can just let it get on with the quiet miracle it wants to perform. To be honest it's all but impossible to stop a cold heap from making compost. If things get too cold in winter, then it all slows down a bit, but as soon as the temperatures start to climb again, the same wonderful processes take over. And you don't have to do a thing. It's best to simply forget about having a compost heap at all, except when you add stuff to it.
Enough waffle. To make a good cold compost heap, you find an area in your yard that won't be disturbed for a year or so, and start building a pile of vegetable matter. Ideally it should be on soil or grass, not concrete or asphalt. Soil means the worms will come into your pile as soon as they realise how much food you are giving them. Use rotten fruit, melon rind, vegetables past their sell-by date; potato peelings; tea bags, coffee grounds; stale bread if you have to. Anything that was once a plant.
Newspaper works if you separate each sheet and chop it up, or scrunch it into a tight ball, otherwise it can take a while to break down. Ashes from a fire are good, though they need to be distributed as the alkaline residues can upset the balance of your pile. Egg shells are a great source of calcium, but crush them up into small pieces first, or they will remain intact for years after putting them on the heap. Most guides suggest avoiding meat and animal remains. This is mostly because it tends to attract rats and other vermin, but also because of the smell as it rots. I have found that you can put human hair on the pile with no ill effects. I take the yucky stuff from the shower drain, let it dry and then chop it up and scatter it on the heap.
That is all there is to it. I don't really know why this piece is so long. I suppose I could suggest that you spray it with water once a month, or that you could go out there in the cold with a fork and mix it all up once in a while. Or that you throw an old blanket over the top of it to keep it warm and cosy at night. There's nothing to stop you doing any of those things--or all of them, but there's no real need for it.
If you do the mixing, tending, nurturing thing, you'll get that fantastic aroma of growing forests and industrious bacteria, and it might speed the process up by a week or two, but that kind of intervention will disturb the beetle larvae and worms and fungi that are quietly eating all your refuse and turning it into the best thing your plants ever grew in. If you want to mess about in half-decomposed compost and get all the smells and good feelings, that's great. But if you prefer to let the worms and bacteria do their work undisturbed, that's perfect too. Compost heaps.. so much less complicated than women, or boyfriends.
If the idea of putting rotten cabbage leaves onto a pile in your garden puts you off--and frankly, I can see how it might--then make leaf mould. It's just as good, but much more neighbour-friendly than rotten vegetables. Leaf mould is a special term for compost made exclusively from fallen leaves.
You know how in Autumn those leaves fall everywhere and it's a pain to gather them up. Here's a tip. if you can get one of those garden vacuum cleaners, use it to suck up the leaves and smash them into pieces. Then put all the smashed pieces into a large wooden box, or a plastic bin bag with holes in the sides; soak them with water and leave for six months. Add some activator if you must.
On the carbon/nitrogen layer thing, if you have spare grass clippings, mix them up with the smashed leaves. By spring time, just when you want to put the annuals into the garden, that dry mixture will have become the most glorious material you could imagine for planting your bulbs.
I'm told that oak, beech and hornbeam make the best leaf mould, but that's largely because their leaves are relatively small. London Plane, Horse Chestnut and other trees have large leaves with thick stems. It's almost essential to smash these up in a machine unless you are happy to leave them to mulch down for a couple of years. Most of us don't have the patience for that, or the space in our gardens.
Leaf mould is especially good for the garden. Like compost, it has all the fibre and nutrients the plants need, but unlike compost it has extra minerals, sucked up by the tree when the leaves were growing. By breaking them down and converting them to compost, you release those minerals once more to feed your plants.