[justviolet]

Today's job is nailing the compost bin back together, lots of the wooden side planks are led on the floor.

The last chap had black plastic sheeting all up the sides, over and as far as I can see under the compost heap too. I'm not sure if I should keep it this way. Does the air need to get in? I'm wondering if it was like that for winter? I'm going to try to dig it over, get out weeds and generally turn it.  It is huge, about 2 metre by 2 metre. Do you think that this is too big now its only a half plot? 
Any advice would be much appreciated.

[Jamie Butterworth]

Idealy, if you let air in it will spped up the process

But you shouldnt realy have the black plastic underneath as that would stop the worms coming up and helping to compost it all

[JayG]

You're the first person I've ever heard suggest they might have too much compost-making capacity!

Yes, compost heaps do need some air, although it's not a bad idea to cover the top to stop it getting too wet.

Some people find that unprotected heaps attract rats (depends on how big the gaps in the sides are of course); you may want to consider covering with chicken wire, which would also usually mean underneath it as well, which is something I don't imagine you are keen to do with it being full!

In your position I'd just repair it, cover the top and then hope for the best rat-wise!

[justviolet]

Do you know what JayG I think you are right. It will be there for the rats and the fox. I have a lot of faith that the chap who had the allotment last knew what he was doing and this puzzled me because the pictures in books that I'd seen were open and I'd read about turning to get in the air etc like you say Jamie. Now it makes sense. I wish I could invite the last chap down for a brew! He knew what he was doing and I feel like I mustn't mess it up!

Thanks for the advice, it really helps.

[justviolet]

Filled two big bags of horse tail roots from the bin as I turned it over! Oh my!

Just reading about ammonium sulphamate as a 'compost accelerator' that just happens to kill the stuff.

Wonder if anyone has any experience or advice on how to use this?

[Comfortably Numb]

Filled two big bags of horse tail roots from the bin as I turned it over! Oh my!

Just reading about ammonium sulphamate as a 'compost accelerator' that just happens to kill the stuff.

Wonder if anyone has any experience or advice on how to use this?

Banned I'm afraid.

Have a look at John's article on it
http://www.allotment-garden.org/garden-diary/189/ammonium-sulphamate-weed-killer-banned/

[Kristen]

Only banned as a weed killer, not as a compost accelerator, and its an interesting idea that composting marestail / horsetail roots using it might well have the effect of compost acceleration and killing the roots.  Not sure if the route it used to use (when it was a weed-killer) was by accelerating the growth of the plant - if that's the case then maybe it won't work as a killer in a composting environment.

Alternative route for marestail / horesetail is to drown it in water for several weeks. The resulting liquid is a good plant feed (as weed roots generally draw up nutrient from deep in the soil), and then chuck any residue on the compost heap.

[Salmo]

Back to the topic.

With a bin as large as that you will probably only ever add thin layers at a time and the compost will not heat up.

You would be better with 3 smaller bins. One being filled. One maturing. One with compost being used. It is usefull to be able to move the contents from one bin to another as this encourages you to turn it.

If you have already re-built the bin why not put a divider in to make 2 smaller sections.

I would not line the bin but I would have something to cover it to keep it from getting too wet. You can always add water but you cannot take it out.

[Kristen]

Interesting about lining, or not. I was always brought up with slatted bins so that the compost heap could breath.  I know only have plastic Daleks, which don't have any of that advantage (maybe Daleks are more prone to creating a slimy (anaerobic) mess? although I haven't had that problem).  Either way, a decent heat will speed up the process, and that needs enough "size" so that heat is retained, but also enough depth of new material added to keep the process going, so as Salmo says the dimensions should suit the rate at which you can fill it.

There is a video of an award winning allotment holder's plot, and he has 3 or 4 bins of diminishing size, which allows turning of C-to-D, B-to-C ... A-to-B, which takes into account the amount of shrinkage as the compost decomposes.

Edit: Found the video. Compost bins are 38 seconds in.
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[Ma and Pa Snip]

We have 3 types of compost bin for our garden veg,

1 x  Slatted about 1mt sq
1 x Tumbler bin
1 x Square 'Dalek' bin type

Most effective is the tumbler, followed by the slatted with the dalek type coming in a very poor 3rd.

The dalek bin one, not only being the slowest also tends to be the the one that the compost stays in a slimiest state longer for, which I would put down to it being the one with the least side aeration vents.

[Benandbill]

Nice topic!  I only have half a plot and my bin is just 3 ft by 3 ft.  It's made of bits of chip board joined with harder wood.  I'm surprised it's lasted as well as it has but it does require a bit of repairing now as the front is cracked.  I've got some black plastic sheeting I cover it over with but loads of air gets in.  I've been toying with the idea of getting it a transparent cover  for the summer to give it a bit of a greenhouse effect so it will get really warm.  Not sure if this is a good idea or not though.

[bigben]

I've been toying with the idea of getting it a transparent cover  for the summer to give it a bit of a greenhouse effect so it will get really warm.  Not sure if this is a good idea or not though.

The downside of this is it gets and "live" stuff in it growing nicely. You might be better with a black cover that absorbs the heat so warms it up but cuts out light so stuff will germinate in the warmth but then not have the light to grow well.