The compost bin

I haven't yet got the SFG bed put together, but one thing I have managed to get going is my compost heap:


That door in the background is my neighbour's back door!  I asked permission before installing the bin and have guaranteed there will be no smells.  This adds to my nerves but so far all I detect on my regular checks is earthy smells, so I guess my prior study is paying off.  It's only about one-third full, despite regular visits to a fruit and vege shop 5 minutes' walk away for scraps, which I chop up before adding, and then sprinkling with sawdust from a pallet manufacturer (big thanks to OG), or some shredded leaves, and giving it a good watering.  It seems every time I make a deposit the level is the same as the last time!!

I'm also adding the household scraps to it, plus the neighbour's ones, but they don't amount to much volume.  I'm trying to get good variety from the fruit and vege shop, but often all I can get is broccoli stems, cabbage/lettuce outer leaves, and if I'm lucky some spinach leaves.  I wonder if my compost will be a good balanced meal for my plants next year.

Once I managed to get quite a bit of fruit which was great, including two apples which were so badly rotten I had to read the plastic stickers to know what they were!  How we change: I now get excited over rotten fruit!  A week later the fruit flies were a sight to behold, but a good smothering with grass clippings and more sawdust seems to have solved that.

The bin is made of plastic-covered polystyrene and is a hotbin system.  Capacity is 13.3 cubic feet (350 litres) and it claims to make compost in "2+ months".   It has a cover/lid, a sheet of the same stuff as the walls, and sits on plastic mesh on top of bricks, for airflow.  Initially the temperature stayed at ambient levels for ages; after the fruit layer things finally started to cook but unfortunately I haven't managed to add any new material for about two weeks and it's pretty much back to ambient again.  I've thought of buying some sheep pellets to help things along a bit more, but haven't got around to that yet.  They're surprisingly expensive in this land of sheep!

I bought this bin 23 years ago if you can believe that, and it's been sitting in our garage ever since.  Frankly if I was buying a bin now I think I'd get something like a dalek.  Stirring the mixture is hard when the level is low – I'm constantly worrying about breaking the polystyrene as I bend over the sides – and you can't get finished compost out from the bottom.  When the mixture is finished you undo the ties in one corner and simply unfold the walls, leaving the compost sitting on the mesh base.  So, it's all or nothing.  I suspect I'm going to end up turning it at least once, which according to the 'manual' is not supposed to be necessary.  Still waiting and seeing on that.

KiwiSFGnewbie wrote:I'm also adding the household scraps to it, plus the neighbour's ones, but they don't amount to much volume.  I'm trying to get good variety from the fruit and vege shop, but often all I can get is broccoli stems, cabbage/lettuce outer leaves, and if I'm lucky some spinach leaves.  I wonder if my compost will be a good balanced meal for my plants next year.

The simple answer is, Yes that mixture should generate good quality compost. Hint: For tough stems such a broccoli, brussels sprouts, etc., split them lengthwise to speed up composting -- the outer skin is so tough that microbes cannot penetrate them, and splitting them allows easy microbe access.

The primary problem with those types of compost bins is that there is not sufficient volume to create the compression & heat necessary to generate the heat for composting.  The minimum size for a compost bin to be highly successful is 3' x 3' x 3', or a cubic yard. Once a bin that size is full, it composts quickly.  I have a 3-bay compost bin, with each bay being 46"x46"x46".  This fall one bay was completely filled with yard and garden cleanups, including spoiled fruit from the trees.  Already that bay has composted down to the point that the bay is only half full.  But, I use compost tumblers for kitchen scraps, coffee grounds, juice bar pulp, etc.

OhioGardener wrote:

KiwiSFGnewbie wrote:I'm also adding the household scraps to it, plus the neighbour's ones, but they don't amount to much volume.  I'm trying to get good variety from the fruit and vege shop, but often all I can get is broccoli stems, cabbage/lettuce outer leaves, and if I'm lucky some spinach leaves.  I wonder if my compost will be a good balanced meal for my plants next year.

The simple answer is, Yes that mixture should generate good quality compost. Hint: For tough stems such a broccoli, brussels sprouts, etc., split them lengthwise to speed up composting -- the outer skin is so tough that microbes cannot penetrate them, and splitting them allows easy microbe access.

Oh that's great news! Thanks so much   And thanks for the hint, too -- I've been chopping across the stems, but hadn't thought about splitting them.  Will definitely do that too.

The primary problem with those types of compost bins is that there is not sufficient volume to create the compression & heat necessary to generate the heat for composting.  The minimum size for a compost bin to be highly successful is 3' x 3' x 3', or a cubic yard [...] I have a 3-bay compost bin [...]  But, I use compost tumblers for kitchen scraps, coffee grounds, juice bar pulp, etc. 

Oh dear, so my 13.3 cuft is less than half the size needed....  It looks like a cubic metre, which I thought would be about a cubic yard.  Well, as I read somewhere, compost will happen anyway, just over a longer time!!!  So long as it doesn't cause neighbour problems I'm OK with it taking longer.

Thanks also for the idea of having different sized bins for different needs.  I wouldn't have thought of that.  Not sure whether I will do it, or simply get a dalek next summer! I'm not convinced that I'll be generating a huge amount of garden waste.

I concur with OG.  You don't have to have a wide variety of fruits and vegetables for good compost.

Think of "leaf mold" compost.  All leaves.  Many purchased composts are made from two or 3 production wastes, depending on location.  Tomato processing wastes, winery solids, rice hulls, brewery spent grains, poultry or daily/feed lots, almond hulls (here they are feed to cattle), stable used bedding straw soiled or not, etc.  High carbon/brown materials such as lumber mill sawdust and chips, straw (after harvesting the grain), and green waste collections.  It doesn't take a lot of "greens" such as produce, manure or alfalfa to make good compost. Most of the volume will be "browns".

Having at least 2 units helps.  I only had 1 and in order to turn it, I had to fork the 1 cubic yard material onto a tarp and then refill it, top to bottom and inside to outside.  If you can make a bin 2.5' x 2.5' x 2.5' inner diameter to set next to it, with removeable front slats, you can easily turn the material.  You will have to lift off the one you have to access the material but it would be at least half easier.    

This photo is of my single 3'x3'x3' I.D. bin.  This is day 20 after turning 4 times.  You can see how much it has shrunk from when it was first filled up to the top.  I covered during rainy days.

Good point about the leaf mould! (and all the other composts out there)   

Turning my material shouldn't be as hard as it might appear.  The product came with a second mesh bottom and I have extra bricks, so I can untie the walls and fork it onto a new base.  I am however wondering how my delicate back will react......  Thinking of doing it over a number of days.

OTOH I can always just wait.  I won't need this compost until next October!

What a beautiful compost heap!  You have the most beautiful garden I could ever imagine   An inspiration to us all.

This free e-book (PDF format) has a good section on composting with a lot of good tips & suggestions.  The composting section begins on page 9 of the book, and there are a couple good charts on the C:N ratio of things to use in the compost.

https://www.seattle.gov/Documents/Departments/Neighborhoods/PPatch/Organic-Gardening.pdf

Oh, way cool!  Thanks OG, this looks awesome