Composting Advice

[cwhaley]

I’ve got lots of 9x2 timber left so decided to build an area to make compost. I spend a fortune on it every year but I have been convinced composting is the way to go. I understand what should go on it (mixture of ‘green’ and ‘brown’ materials, layered) but I’m not familiar with how it should go on it.

I’ll build two bins adject to each other about 5ft x 5ft each. My questions are:

- Do I need to cover the bins with a lid?

- How often do I need to ‘turn’ the material?

 

[Mottie]

I suppose you'll get as many different answers to that as in a 'what’s the best boiler' thread! Over our allotments everyone is different. We have covered, uncovered, turned, unturned, gaps for allowing air in, no gaps to keep the heat in etc etc. Personally, I have three regular composting bins. I keep the lids on as I want the heat to help break the compost down and I might just turn them once in a year - putting the top layers to the bottom and the bottom on top. If nobody is about, I pîss on them which is supposed to be really good for the composting process!

 

[JohnD]

Assuming you fill about 1 bin a year. That means your bins are about the right size.

Load bin 1 until it is full. During the winter, after you have put your autumn leaves and final mow into it, turn it into bin 2, mixing well. That means the newest stuff will be at the bottom and will have max extra time before you use it. Put the stuff from the edges into the middle.

Fill bin 1 again with fresh stuff. When you approach turning time, the following year, dig out bin 2 and use it. If you are not ready to use it, you can turn it onto a surface ready for use. You can have a bin 3 if you want, or have a lot of thick stuff that is slow to break down. Or you can throw the slow stuff back onto bin 1. If you find you have more finished compost than you think you need, put it on your beds or round bushes as a mulch, with their stems rising through it, after weeding, and it will suppress weeds. By the next year it will have rotted away and the worms will have pulled it down, thus improving the soil.

 

[pidgeon1]

. If nobody is about, I pîss on them which is supposed to be really good for the composting process!

You could ask your neighbors to help with this

 

[Mottie]

It’s a mother and daughter neighbour I have and the composting bin might be a bit too high for them.

 

[StephenOak]

I would basically agree with what @JohnD said.

I currently have two wooden bins, each c. 1 cu. yard, and I keep on adding stuff to bin 1 until it is full then I empty it into bin 2. During the course of adding stuff to bin 1 it may well reach the top but a while later will have gone down making more room - that can happen many times before the bin is really full.

Moving from bin 1 to bin 2 is the only time that I turn mine, but then I am not in any hurry. In bin 1 the material breaks down into smaller pieces so it mixes up much better and when it goes into bin 2 it breaks down a lot more.

If the brown and green materials are quite distinct (e.g. wood chip and grass) then then layers need to be quite thin as the bacteria that do the work will only really grow on the interface between the brown and green layers. Moving from one bin to another will mix everything up.

Anything at all firm needs to be shredded, to maximise the surface area available. I have loads of ivy in my garden. When I have put a bunch of that in, upon moving the material the leaves will have fallen off but the ivy stems will be intact and seem to have been acting a bit like a spring, keeping the material apart. So I always use a pair of shears to chop up ivy, and anything like that, into shorter pieces.

I don't cover mine, even so when I have got the ratio right and the material well mixed I have got it up to 70º C and I regularly get it above 50º.

The bacteria need water and I add (at least ) one can of water whenever I add a significant amount of material. When I move it from bin 1 to bin 2 I get a mate to hold a hose putting a mist of water onto the material as it goes in.

 

[Mottie]

I always leave a broken paving stone on top of my compost to press it down.

 

[scbk]

You might be better selling the 9x2 (or using it for something else) and buying a few of the plastic compost bins, the standard size for them is 330l

5ftx5ft is pretty big, assuming 1m high, that's about 2,200l ! How long would it take you to fill that? If you have a number of smaller containers, you can have one or two being filled, one being slowly emptied, a few full and left to rot.

 

[scbk]

My thought was always if the rain can hit the compost, it is washing away the nutrients.
I built a big covered compost area, but it is probably a bit too dry now. Depends how much greenery you add.


P1ss is good.

 

[cwhaley]

Thanks all for the replies, especially @Mottie @JohnD and @StephenOak -- plenty to go from there. I've attached a picture of the 'bins' as they currently are. Excuse the untidiness (bottom end of the garden currently in progress!). The posts at the front still need to be cut down, etc. I will go with a lid on it -- I've got a huge roll of DPC so I'll make a frame with ply on the top and cover with a few layers of it, hoping it's UV-resistant...

Fine with building layers throughout the year and then turning over into the empty bin. Seems like a fairly low-maintenance task. I'll have the left-over spent compost from this year, so I'll layer that with green/brown waste, cover and leave over Winter.

5ftx5ft is pretty big, assuming 1m high, that's about 2,200l ! How long would it take you to fill that? If you have a number of smaller containers, you can have one or two being filled, one being slowly emptied, a few full and left to rot.

Thank you. I've reduced them slightly in size and they are 27" high. Each year I have ten baskets, fifteen pots for flowers and now with more veg I'll be filling about fifteen pots. I have been buying/given between 800 and 1000 litres a year so I will get through it!

 

[StephenOak]

and buying a few of the plastic compost bins, the standard size for them is 330l

IME they are a lot less effective due to their relatively low size.

The bacteria that do the initial breaking down like warmer temperatures. The outermost layer of compost acts as insulation and so a larger bin will have more compost that is, say, 6" from the edge and thus well insulated and better for the bacteria.

 

[Odds]

@StephenOak raises a good point regarding temperature: a regular temperature will break down compost much more effectively and a bin with a lid, or covered with plastic, will be preferable to create the ideal conditions for microbes to get working...

'The heat generated during the thermophilic stage of hot composting is the most important factor in the elimination of plant pathogen in the organic materials. However other factors such as competition for nutrients, the production of toxic compounds, the activity of enzymes produced in the compost and the production of antibiotics and parasitism within the heap also play a role.'

(read on @carryoncomposting.com)

 

[cwhaley]

@StephenOak raises a good point regarding temperature: a regular temperature will break down compost much more effectively and a bin with a lid, or covered with plastic, will be preferable to create the ideal conditions for microbes to get working...

'The heat generated during the thermophilic stage of hot composting is the most important factor in the elimination of plant pathogen in the organic materials. However other factors such as competition for nutrients, the production of toxic compounds, the activity of enzymes produced in the compost and the production of antibiotics and parasitism within the heap also play a role.'

(read on @carryoncomposting.com)

I'll have a read of that, thanks.

I am going to put a lid over each bin to create a bit of insulation for heat and deflection of rain.

 

[cwhaley]

In the end I went for the one bin. The section on the left I'm going to use to store all the plant pots in Autumn. Again excuse the dump -- it's an area of the garden which has had a lot of work over the past year.

So far I've got about 6" of green waste (old weeds, grass clipping, veg peelings, etc), then soil/water to about 2" depth, then a load of corrugated cardboard and newspaper. I'll repeat that until I reach the top.

 

[Mottie]

Be careful about putting weeds in there. You can put the leaves and stalks in but I’ve read that you shouldn’t put the flowers/seeds/roots in there.