Compost heaps and bean trenches

Posted: Friday 5 September 2014
by Kate Bradbury

I conducted an experiment on the allotment this year: rather than putting weeds and kitchen waste onto a large heap, I dug them into a trench.

Runner bean trench

I conducted a little experiment on the allotment this year: rather than piling all the weeds, kitchen waste and other compostable material into a large heap, I dug a trench along the width of the plot and piled everything into that, instead.

It was hardly groundbreaking – it’s nothing more than a bean trench. But my neat little row of compost works a treat. Being in the centre of the plot it has become a hub of sorts; it’s where the greatest number of worms is found and where the soil is richest. Slugs and snails are drawn to this area too, which keeps them away from my salad crops and makes them easy to dispatch (although I’m losing that battle – the slugs seem to have taken a particular liking to the taste of aubergine).

I like to think the trench also works as a wildlife shelter. Too often wildlife habitats are all together at one end of plot, forcing frogs and small mammals to travel across large areas of cultivated land. Having a mini stop-off point in the centre of the plot hopefully provides an additional area of shelter, between the scrubby patch at one end of my plot and the long grass at the other – it’s a wildlife corridor if you like.

My trench is also productive: In May I created three planting holes in the waste and planted butternut squash in the soil, with the view that the plants would scramble up the south-facing bank I’d created. Partially sheltered from wind, a sun-trap and with nutrient-rich, moisture-retentive soil, it’s the perfect spot for hungry butternut squash plants – I currently have 10 large fruits ripening up nicely.

But I miss having a compost heap. A proper one, into which I can plunge my fork and turn to reveal a steaming mass of worms and bacteria; and waste which doesn’t disappear into the soil but which I can sieve and use as a mulch or top-dressing for pot plants. I love sieving compost. The active process of composting is lost with a bean trench – bean trenches just aren’t as fun.

So next year I shall have a large, steaming compost heap, but I’ll also make another little trench in a different area of the plot, so the worms and nutrients can improve the soil somewhere else. As for the current trench, I’ll soon cover that up and let the remainder of the waste rot into the soil. Then next spring I shall grow beans in it. It’s what bean trenches are made for, after all.

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Talkback: Compost heaps and bean trenches
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oldchippy 05/09/2014 at 14:25

Kate my Dad did this on his garden as the soil was not very good,he grew some good veg every year,Kate I thought that your plot was only for 6 months as they were going to build on it.

Steve 309 05/09/2014 at 16:52

Isn't this standard practice for runner beans?

bekkie hughes 05/09/2014 at 16:54

We always did it on the allotments i was on, i think this way of composting seems to have fallen out of favour, i think its very useful

Kate Bradbury 05/09/2014 at 18:51

Hi Oldchippy, yes it was only for six months but they've not made a decision yet and they've also given me a second half plot, so good news all round!

Steve 309 - yep, traditionally standard for runner beans although I don't know many people who practice it now (apart from my dad!)

Steve 309 05/09/2014 at 18:59

...and me.  And my best friends.  And our other friend who runs a garden for....   It's alive and well in SW Lancs!


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