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Compost heaps in winter

  • Compost heaps in winter
  • Compost heaps in winter

At the end of a busy season, the current compost pen is often well filled, and it's very tempting to top it off with the grass from that final cut - which, this year, was in December for many of us! - then leave it over the winter to get on with composting itself.

This is all well and good as long as you don't leave the grass piled into a conical heap, as per the first picture above. All this does is create a nice waterproof thatch to the pen (after all, thatching is done with straw or reeds, which are both, in effect, long versions of grass) which prevents any water getting in, and the conical shape just helps the water to run off even more quickly.

In all the years I have been gardening, I have seen far more compost heaps that fail for being too dry, than ones that are too wet: dry material won't rot!

An additional problem is that the thick layer of grass also heats up for a brief period after you pile it on, so you get a layer of dried-out material which is even more impervious to water, and which kills all the worms which would otherwise work hard all winter to make the compost.

Whenever I find a compost heap that has been piled up like this, I take the time to rake the grass out towards the edges, stuffing it down well into the corners, and making a depression in the centre, so that any rain will run into the pen, not out of it.

You can see this in the second picture: much better!

I also push a few vertical holes in the grass layer, so that the water can run through it, instead of sitting uselessly on top of it.

This means that all the winter rain will go into the pen, and by spring it will be well on the way to being processed into good useful compost, instead of sitting there going stale all winter, with little worm activity to keep it aerated.

So pop out and check your compost heaps before it gets too cold: make sure they are more or less level on top, with a central depression, and no big gaps in the corners.

Then you can go indoors and enjoy being inside through the worst end of the year (weatherwise), knowing that your garden waste will be gently turning into compost, while you are staying snug, and looking at seed catalogues!

Comments (7)

  1. Grower

    Martin Doyle

    Thank you - great advice! I do find that plastic bin composters are very prone to being too dry. I have compost heap envy - wish we had the space for larger bins!

  2. Grower

    Amanda CW

    Great advice - I had never even thought about this. Thank you Rachel!

  3. Grower

    Rachel the Gardener

    You're most welcome - I am kinda evangelical about compost!

    Martin, I'm envious of these ones myself, as they belong to one of my Clients. Plastic bin composters ("Daleks") are not trivial to manage! Apologies for the relentless self-promtion, but I've actually written a book about compost, which does contain a whole section on how to manage daleks...

  4. Grower

    Stafford Lake Nursery

    We generate mountains of oak leaves, amongst other things, to compost here. I always find they decompose much better if they are damp when we are gathering them up.

  5. Grower

    Rachel the Gardener

    Oooooh, (wincing face) I have to say I'm not keen on putting leaves on compost heaps at all. Anything more than a couple of handfuls of tree leaves will ruin a compost heap: their decomposition process is quite different.

    Or do you mean that you make leaf mold out of them?

    If so, then yes, when making leaf mold, as with making compost, dampness is essential!

  6. Grower

    Stafford Lake Nursery

    Leaf mould. Makes a superb soil conditioner!

  7. Grower

    Alan Wardle

    On the subject of compost. I have about 3 cubic metres of well composted hay and vegetables and rabbit droppings. It is very good to break down clay or for compost for vegetables.
    Its free to anyone who wants it , just bring your own bags,
    give me a ring if your interested.

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