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How to make a composting trench


A composting trench is a great way to use up your organic kitchen waste and give your vegetable crops a boost in the coming growing season. By placing your vegetable peelings in a trench to rot down over winter, you'll add nutrients to the soil and help to retain valuable moisture. All it requires is a little forward planning, as you need to select in advance where you're going to grow your beans or other thirsty crops, such as courgettes.

How to do it


Dig out a trench about 60cm deep during late autumn or winter. Then start filling it with all your organic kitchen waste, such as vegetable peelings, mouldy fruit, apple cores, onion skins and even tea bags.


Each time you add a batch of kitchen waste, cover it with a layer of soil. Continue until the trench is full, then top off with soil and leave it to rot down. As it does so, it will hold on to plenty of moisture, which is just what beans enjoy. 


In May or June, sow or plant your beans on top of the composting trench and their roots will go down into the moisture-retentive, nutrient-rich material, boosting their growth.

Discuss this project

Talkback: How to make a composting trench
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Tom Freeman 29/11/2012 at 17:20

Is this sufficient time for the material to rot down sufficiently to enable planting on top in May/June?

jo4eyes 29/11/2012 at 17:28

Yes, is the short answer.

Some years, eg last, I couldnt start my 'bean trench' for this yrs' crop until the next Spring. Ok, not all the vegetable waste that I'd used had completely rotted down, but by the time I dismantled the wigwam in late summer- very bad yr for growing for me- no sign of the trench filling remained & the soil was in good condition.

I now try & adopt the trench policy to improve any new bed that I start, which is usually from removing more of the lawn! J.

barbara54 29/11/2012 at 18:06

I do this each year, even in my small veg patch. Used to do it for my long bean trench in my previous garden. Great feeling of satisfaction as it all goes and nourishes the soil.

Verdun 29/11/2012 at 18:23

Yep, all my compost from one bin, rotted and partially rotted, goes into a trench for runner beans. Earlier the better but now is a good time to do it. I add a little fertiliser in spring too but I grow masses of succulent runner beans.

Hammy2 30/11/2012 at 00:46

I use Bokashi for my kitchen waste. Can I use the contents of my filled bin in the composting trench?

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