Let’s Build A Compost Bin!

A few weeks ago, I wrote about the compost bins at the Priory (see “Composting the Priory“) and was inundated with one request for more information on how I built them.  So, for what my carpentry skills might be worth, here we go.


A couple of years ago, I picked up a copy of Geoff Hamilton’s ‘Cottage Gardens’ in a charity shop.  And within this lovely book, I saw his design for a rose arch and decided that I would build one in our garden.
Here it is (after a rust infested R. Iceberg was removed from the right hand side).  The success of my rose arch gave me the confidence to build two wood stores, a couple of simple garden benches and compost bins.  The ‘bins were very loosely designed around the concept of the rose arch.  Four posts (7cm x 7cm) are sunk into the ground and boards simply nailed to the posts to make a three-sided box.
Add two more posts within the box for each additional bin.  Make as many as you can and more than you think you might need.

The boards I used were 15cm wide and 4.8m long: the length actually determined the width of the bins – I simply divided the length of one board by three which gave me three bins, each 1.6m wide.  A board cut in half gave me the depth of the bins: 2.4m.  Six boards nailed to the posts made bins 90cm high.  You may, as I did, over-engineer the fixing of the posts into the ground and use post spikes.  These are long spikes that you first hammer into the ground, with a square bracket at the top that holds the posts.  BUT they are a pig to use.  They invariably twist as they go into the ground and as they must stay square, this is a real pain.  Also it is very hard work sinking them into the ground.  So don’t use spikes.  Do as I did at the Old Forge and just dig a hole two feet deep for each post and then back-fill with hardcore and postcrete (a ready-made concrete mix).

The Priory Bins

The bins I’ve made for both the Old Forge and the Priory are very big but that is because they must accommodate a ride-on mower and trailer.   Make yours to a size that suits; in my own garden, the bins are 1.5m wide but only 1m deep.

Back view of the Priory bins

I planned to build two sets of three bins at the Priory and realised that if I spaced them correctly, I could have a seventh bin formed from the gap between the two.

Finally, screw or nail a batten to the front edge of each post at the front of the bins (the red piece of wood above) and to that, attach a vertical length of planking equal to the height of the bins.

Here’s a close up of that arrangement with one of the front boards shifted slightly out of position.

You can then cut six planks to slide down the front of each bin.  Strictly speaking you don’t need to do this but it does increase the amount of compost each bin will hold without spilling out of the front. Site your bins in the open, not under trees: you want rain to fall on them.  Build them on level ground if you can – it’s far easier than building them on a slope.  And should you cover the compost?  I do.  It keeps in moisture and warmth; and keeps out weed seeds.

And that’s it.  If anything’s not clear – please say.

I love my compost bins.

Composting the Priory

I like making compost bins.  I can’t seem to stop.  Stick me in a garden and before you can say, “Sticky Toffee Pudding,” I’ll have knocked up a range of ‘bins.   Whether you want me to or not – I just keep on building them:

whether at the other garden I tend;

My own garden with partially built compost bins on left with raised veg beds, olive tree and Jim, Spring 2011

in my garden;

The Priory compost bins, with mixed hedging on left – freshly cut a few weeks ago with clippings waiting to be burnt in foreground

or at the Priory.  I’ve written about the compost bins at the Priory before (see “Compost, Compost and Yet More Compost“).  They sit out on the footpath over on the western boundary.

The front of each bin has six boards that slide up and out

The bins are big: five foot wide, eight foot long and three-foot high and with seven of them you’d think my composting facilities could take all that I could chuck at them.  But, of the seven bins only three were, until recently, available for this season’s grass clippings and garden waste.  Two were filled with last year’s compost and two with last year’s leaf mould.  The gardens produce so much  in the way of lawn cuttings  that I was worried I’d exceed Priory Composting Capacity.

My lovely, lovely leaf mould is in the bottom two bins.

Recently though, and since the above photo was taken, I’ve managed to amalgamate all of the leaf mould into one bin and, by now having four available bins, averted Complete Composting Chaos.  Shudder.
I turn the contents regularly to add much-needed air into the mix and help speed the composting process.  Ideally though, there should be a lot more other plant material mixed in with the clippings.  Left to their own devices and unturned, heaps of clippings mixed with a similar amount of ‘brown’ waste (i.e. leaves, cardboard, paper, etc), should heat up to an extraordinary degree and produce wonderful compost in about three months.  Grass clippings on their own also heat up amazingly but need to be turned regularly if they’re not to become a slimy, foul-smelling mess.  In the above photo the grass clippings are fairly young and yeah, boy do they stink.  Really.  I suppose this is understandable considering that they are being digested, consumed by heat, microbes, fungi and bacteria with, hopefully, sweet-smelling compost as the main waste product.

This collapsed cardoon is actually off to the bonfire – its stems are too woody for the compost bins.

 I add huge amounts of waste to the bins.  Trailers and trailers of stuff.  Wheelbarrows and wheelbarrows of stuff.  And yet it all continuously breaks down and reduces in bulk.  ALL of last year’s garden waste now sits in one and a half bins.  Remarkable.
In a bid to help the breakdown of all those grass cuttings, I add as much brown waste as I can.  The bins devour all the old paperwork from the theanxiousgardener.com offices, as well as increasing amounts of cardboard, newspaper and kitchen waste from the Priory; and recently the chopped up beech hedge clippings too.  The sheer bulk of the latter was perfect for mixing in with the smelly grass.  Obviously all the general garden waste (dead plants, prunings, etc) is also added to the heaps, as well as some wood ash from the house fires.
I was seriously worried with the overwhelming amount of cut grass I was adding to the bins last year.  But I continued to turn them from one bin to another (great upper body workout) and to add more and more newspaper and cardboard and leaves.  And, miracles of miracles, it seems to have worked.  Look – chock-a-block full of worms and what was nasty, foul-smelling gunk is now becoming lovely, pretty much odourless, compost.  So much so that I’m happy to stick my hand in it.  Wouldn’t have done that a few months back!

The Long Borders – Aug 2011

I’ll use all of this compost during the coming autumn and winter months as a mulch and improver for the beds and borders; and reduce the considerable amount of mushroom compost that I usually buy.
And all the money I’ve saved can be spent on tequila.