The bottom of the heap should be open to the soil. If you are likely to have a problem with Rats put chicken wire down, so they can’t get in – and possibly bring it up the out-sides a foot or two – they are liable to gnaw at the base
I’m afraid at the moment I am just chucking everything in a heap but when-I-were-a-lad I used to put a thin (1/2″ – 1″) layer of soil every so often (every foot or two) and a 2″ – 3″ layer of manure (preferably fresh).
So I’ve stopped being too concerned about the mixture of materials in my compost bin because the reality is that composting material comes in bursts. You feel guilty and weed the whole garden – so you have a wheel barrow full of weeds – with lots of soil attached – then you mow the grass, so that’s all you have; and then in Autumn you have more leaves than you know what to do with.
I put my grass clipping in a pile. I spread the new clippings all over the top of the pile, so that they are not very thick/deep in any one place – that way they tend not to go slimy / anaerobic. I have a large chicken-wire-enclosed area where all the leaves go; then when I have some material for the compost bin I include some other material from the grass pile, and the leaf pile – and the horse-manure pile too.
Adding some soil definitely won’t hurt, it has the right bugs to kick the thing off. So soil on the roots of weeds, stuff you are chucking out of pots – seedlings that didn’t make it etc. are all fine.
I put the Chicken droppings, from their coup, and farmyard manure on the heap, and when no one is looking I pee on it – which is a good accelerator. If I could find a suitable potty that I could put in the loo for the boys, at least, that would be good.
You can use a compost activator, although you shouldn’t need that, but it might help to get the temperature up. Aiming to get a high temperature is good – it will make the heap rot down more quickly, and thus give you compost sooner, and a decent heat will kill a lot of the weed seeds, diseases, and bugs. Once the heap cools down the worms will move in to munch and mix up the remainder.
A mix of green material and more “stalky” material will help keep the heap “open” (and I’ve seen recommendations of adding loo and kitchen-paper rolls [the cardboard will rot down, but provide “air gaps” in the meantime]. You need to let some air in, rather than just have a soggy mess [which you would get, for example, if you just used grass clippings – although mixing in some grass will help you get the temperature up quickly].
For really “stalky” material, such as the stems of Brussels Sprout plants, you really need a mechanical shredder to cut them up. In the old days we used to beat them to death with the back of a spade first …
You can include shredded paper – we have quite a lot from the office which has gone through a laser printer and is “confidential” and as such has to be shredded before disposal – which, I believe, makes it less suitable for conventional paper recycling. Today’s printer inks are all vegetable dye inks so they can go in the compost heap, but I avoid shiny paper and the plastic from window envelopes (and there is some other junk the office folk are, not unreasonably, inclined to shred – so I bring a box of paper home and get the kids to shred it so that we know exactly what is in there)
Stick some carpet, or somesuch, on the top to keep the rain out, and help insulate the heap. You can have a more conventional lid, but if there is an air gap under it (i.e. a board across the top of a slatted box) then the surface will dry out). The Dalek type have tight fitting lids, which are fine. But do make sure that the heap is not dry – it may even need watering – check how the centre feels now and again.
And if you have the energy to turn the help (particularly mixing the outside material into the middle) that will speed up the process dramatically, and you will have compost sooner, and a more even final product.
Things to avoid: diseased or woody material, meat, pernicious weed roots (like bindweed and gound elder, mares tails, etc.), dog & cat excrement (but bedding from Chickens, Rabbit, Guinea pig (i.e. vegetarian pets) etc. is fine)
Before you start building a compost bin you might want to see if your council subsidises compost bins.
I got a couple of plastic Daleks in 2008 (20 quid each I think) and they have been brill – I had good intentions of building a mega-compost-bin-processing-area 😉 but it wasn’t happening. Some councils also do Green Cones (which will also compost meat), and maybe even wormeries etc. ??
Putting your Postcode in the Recycle Now site should tell you if there are any subsidised bins available in your area
You can also get compost stirring tools
– stick it in and “pull” to mix up the heap.