Root and Branch

Black gold

Compost is the heart of a garden, says Hephzibah Anderson

This article is taken from the January/February 2021 issue of The Critic. To get the full magazine why not subscribe? Right now we’re offering three issue for just £5.

The start of a new year generally means austere regimens of meagre repasts and masochistic workouts, but really, who among us has the appetite for self-sacrifice this time round? Rather than firing up the NutriBullet, why not focus instead on getting your garden’s soil into shape? The secret to that, of course, is the compost heap. 

Akin to a fine wine, the end product inspires lyrical prose and metaphysical musings

Composting sorts the serious gardeners from the put-’em-in, whip-’em-out dilettantes who rely on fresh specimens from the garden centre each season. Rather like sourdough, it’s an essentially simple, low-tech process that has attracted layer upon layer of mystification. Archaeologists date the spreading of organic material back to the Stone Age, and until chemical fertilisers were invented in the nineteenth century, it was all there was. 

Today’s “master composters” are fluent in multiple methods, from pit to anaerobic composting and compost in a bag. If you want a bin, the choices are endless: hot bins, tumblers, wormeries, daleks (they do look very like their nefarious namesake). 

There are recipes, too, in which the ratio of greens to browns (that’s nitrogen to carbon, or mouldy marrows to dry leaves) is contested. Compost needs exercise (turning) and hydration (watering). You might even nestle a hot water bottle in it at this time of year. 

Akin to a fine wine, the end product — crumbly, almost sweet-smelling, and widely known as black gold — inspires lyrical prose and metaphysical musings. George Washington was evangelical about it, while for Bette Midler, making her first heap proved nothing short of transcendent. 

“Behold this compost!” Walt Whitman exhorted in his 1856 ode to decay and renewal. And with good reason: as Merlin Sheldrake observes in Entangled Life: How Fungi Make Our Worlds, Change Our Minds, and Shape Our Futures (Bodley Head, £20), it provides a small-scale physical record of what fungi get up to on a global scale.

Though we tend to tuck it out of sight, the compost heap is the heart of any garden. Never mind the holier-than-thou vibe that sometimes wafts off it along with pungent odours, real compost works wonders for any soil. It helps clay become more friable, and enables sandy soil to better retain water. It’s warming, being of darker hue and therefore absorbing more sun.

And it returns to the earth much of what our plants hungrily take out, including manganese, iron and zinc. Better than something for nothing, compost is something from stuff you were throwing out. In fact, more than a third of the contents of the average household bin can be added. 

At its most basic, composting is all about encouraging bacteria to transform peelings and prunings into something precious, with the addition only of time. Exactly how much time varies from as little as three months to two years, depending on technique.

A confession: I am far from being the most conscientious of composters. Round the back of my allotment, near the communal shed, sit enormous piles of horse manure, wood chips and grass clippings, composting ingredients of which I rarely avail myself.

Low temperatures mean this isn’t the most rewarding season to begin composting

My heap, such as it is, has not been “consciously” assembled, but rather built from kitchen and garden scraps I chuck in randomly. It’s all contained, more or less, in a ramshackle flatpack bin made of slats, and while over the summer I remembered to give it a soaking with the hose, and would every so often treat it to a glug of organic accelerator, I’ve done nothing to insulate it or protect it from cool-weather waterlogging. 

Here’s the thing though: despite my lackadaisical efforts, that pile has yielded shovelfuls of miraculously rich soil. Not many of them, admittedly, but not bad given my failings. 

This being the time for fresh leaves, I’m bent on mending my ways, but for anyone daunted by the apparent complexity of composting, remember the rules apply largely to gardeners blessed with big plots and expansive grounds. 

Turning, for instance. Air is vital for the microbes who’ll work their magic, but there are other ways to get it flowing, especially in a modestly-sized heap. You could poke holes with a hoe handle or add egg boxes and loo roll tubes, which provide aerating structure. Even twigs are a help. 

Low temperatures mean this isn’t the most rewarding season to begin composting, so if you don’t yet have a heap on the go, and don’t fancy indoor composting (nope, me neither), this is an ideal moment to dig — and fill — a runner bean trench.

Dig to a depth of around 60cms, line with organic kitchen waste — sprout peelings, squishy satsumas, perhaps a tea bag or two — and cover with a layer of soil. Top it up as it rots down, always covering with soil when you’ve done so, and come planting time, you’ll have nutrient-rich soil that’s better able to retain moisture for your guzzling runners. 

Now, who’s up for leftover fruit cake? 

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