Tag: compost activators

Composting – is it just a load of old rot?

Just to my left, as I’m writing this, is a bookshelf filled with books about composting. If you’ve followed this blog for any length of time you’ll know that we’ve tried almost every way there is of making good compost; and each of them has advantages and disadvantages. The one thing I can say with absolute certainty is that the heap in the picture above is a rubbish heap and not a compost heap. The computer software saying – “garbage in, garbage out” applies every bit was strongly to compost. I’ve even seen an abandoned bike rusting away on a compost heap.

The favourite starting point for most of us is the one you make from wooden pallets. The advantage is that it’s pretty much free to make and it will produce compost. The downside is that the open slats allow cold air and rats to get in, and if there’s any trace of food waste they’ll come hunting for it. Rats are an ever present nuisance and we just have to accept that. You can line them with chicken wire but rats often dig in by tunnelling underneath and you’ll soon discover when turning the heap that the tines of your fork will constantly hit the netting. Our neighbour bought himself a fabulously expensive hot-bin made from expanded polystyrene and the rats simply ate through it. As for the conical polythene ones that you buy at garden centres or from the council – I can’t say because we’ve never had one – but I hear the rats still get in from underneath.

On the far left above is my version of the California Cylinder which, – when there’s plenty of green waste around – will go like a train. It’s made by forming two concentric cylinders of sheep wire and then inserting thick cardboard into the gap between them. You can also build in a chimney to pull heat through. In one of our gardens, when we cleared it of weeds, we had four in a line steaming away merrily and turning out fabulous compost. The next year we had far less green waste and they were not so successful. The other disadvantage is that it’s all but impossible to turn the heap – it’s better to pull the wire and cardboard off, set it up again somewhere close and refill it with the turned compost.

The simplest composting method of all is the leaf mould heap, like the one in the right hand photo, which is a single cylinder of sheep wire filled with as many leaves as you can press down into it. It takes a year or two but it always works. We find that we can grow a great crop of cucumbers on the heap during the summer while it rots. Even open heaps will work eventually, but then you really have to turn them very frequently and they’ll grind to a halt as soon as the weather gets cold. In the end I built a large four bay composting arrangement with removable fronts which works well for us and makes turning easy -still hard work, though!

Composting is a seasonal cycle

The big challenge is that composting works best when you control the ingredients – mixing green and brown waste and turning regularly. So during the winter months there’s nothing much going in except for veg peelings and the like. Winter heaps don’t often heat up very much, and unless they’re well laced with torn up cardboard and paper, they tend to get anaerobic, wet and smelly. Even in a well managed winter heap, you’ll find that it’s worms doing most of the work. Worms are wonderful. They appear out of nowhere, chew up your waste and turn it into gold – very slowly. In the spring if the heap or the ambient temperature gets warmer they’ll move off somewhere more comfortable without any intervention on our part.

There are two peak green waste seasons – early summer when the remains of winter crops like broad beans go in; and autumn when bean vines and all the rest are cleared away. We move the winter heap with its worms to the next bin and then layer the abundant green waste with any sort of carbon we can get our hands on – cardboard so long as it’s not plastic coated, any sort of dried or dead grass, leaves and – interestingly – wood chip. Just this week our bin reached almost 60C with several 2″ layers of wood chip incorporated. We were confident in adding wood chip because we noticed that we get through around 25 barrow loads every year just topping up the paths. It rots down much quicker than you’d think. We’re lucky because the local council bring wood chip and leaves on to the site during the autumn.

But there are other additives that are invaluable in a compost heap. We use horse manure and even seaweed when we can get it. The last load of seaweed we brought down from the Lleyn Peninsula in North Wales where we’d been on holiday. It stank to high heaven and was full of flies and sandhoppers so it was an uncomfortable 200 mile journey with the windows open; just as it always is with the still warm horse manure that we use in the hot bed. If there’s any spare we add that to the compost as well because it’s so rich in nitrogen and carbon – already mixed.

We also occasionally use chicken manure pellets to steam things up a bit, and drench the heap with liquid seaweed feed now and again if it feels too dry. Control of the moisture level is crucial to success and one of this year’s jobs on the to-do list is to roof over the whole line of bins so we can harvest the rain falling on them and control the temperature and moisture level more accurately.

Of course the finest additive of all is human urine which combines bioavailable nitrogen and moisture at the same time – but don’t overdo it and make sure you’ve agreed with your partner that it’s OK to clutter up the bathroom with a jug and a five litre ex vinegar container marked clearly “Bio-hazard” . We tell everyone we talk to that we’re doing it because it’s an amazingly effective preventative against crop larceny – because they never know which ones we’ve just anointed!

What not to add

Obviously any cooked food and or meat – although I’ve occasionally left a dead rat to compost down because it seemed only fair. Winter heaps should not contain noxious weeds like bindweed because they don’t get hot enough to kill seeds and roots . a very hot summer heap – if it reaches, say, 60C would kill pretty much anything – but you never know. We err on the side of caution always, having introduced creeping buttercup into one of our past gardens via horse manure.

More particularly after wasting many hours picking bits of so-called compostable material out of an old heap; we no longer add those green caddy liners nor any teabags. We open teabags to extract the tea leaves and the compostable bags which seem never to rot, go to landfill. Even worse are the big ticket tea temples that are part of the USP of Teapigs brand. Sorry guys – without a commercial (very hot) process they appear to be invincible; clogging up the beds and any rake you might use. I actually ran an experiment on the little coir disks wrapped in mesh which purport to be green – and they don’t rot either. When it comes to greening up horticulture it pays to be careful – not everything it says on the packet comes to pass! And don’t ever put in a thick layer of grass mowings unless you’ve allowed it to wilt first in the sun.

That’s it really – the sad sum of my composting experience in a thousand or so words out of the fruits of which we can make maybe three cubic metres of compost and one and a half of leaf mould every year. Marvellous stuff ‘though – and so much better than anything you could buy in a shop.

If looks could kill …

A thousand words on poo!

As we turned into the allotment yesterday a light tipper lorry pulled away at great speed and off down the hill. “He was in a hurry” I said to Madame as we pulled over next to a newly dumped pile of manure whose new owner stood regarding it whilst trying to keep her two children out of it. Obviously I couldn’t just ignore the chance to see whether it was as good as, or better than, our usual supplier. It certainly looked alright, but when I took a handful and smelt it, there was a powerful whiff of ammonia. Without getting too nerdy about it, ammonia (NH3) is one of the principal greenhouse gas emissions from cattle farming. It’s generated when ammonium – which is a normal component of fresh manure – breaks down in a double chemical whammy that deprives the resulting manure of nitrogen, reducing its fertilizer value; and at the same time releasing ammonia into the atmosphere as a greenhouse gas. Farmers know about this (I hope) and manage their manure carefully to minimise losses.

We allotmenteers are mostly neither chemists nor farmers but our belief in manure is almost parallel to membership of the local church – we think it’s a terrific thing but we’d rather not get too involved in the theology. On the other hand, cattle produce mountains of the stuff and it can be quite a disposal problem and so combining the excess of poo on the farm with the excess of zeal among the faithful means that there’s a considerable temptation for entrepreneurial tipper lorry owners to solve the farmer’s problem and make a considerable amount of money in the process.

“How old is this?” I asked the allotmenteer who was still getting over the shock of my sticking my bare hands and nose into the pile. “He said it had been stacked for two years”. “Hm” I thought. “How much did he charge you?” “£100 – cash”, she said. There was not much over a cubic yard, around half a ton, which meant it cost roughly the same as my present source which was looking better by the minute.

Years ago I was given the honour of digging out about a four foot layer of horse dung from a stable. I imagine it must have been necessary to sell the thoroughbreds and buy some Shetland ponies, the filthy floor was so close to the rafters. If you want to know what a four foot layer of anaerobic, methane emitting manure smells like please put down your knife and fork now. This is not for the faint hearted; but straw being expensive and occasionally in short supply, there’s a temptation to put as little as possible down and my goodness it shows, or rather smells – acridly, stomach churningly, eye wateringly vile .

On the other hand a friend who runs a stable and lets me have a load of fresh horse manure for the hotbed every year (although not this one because of travel restrictions), is generous to a fault with her straw, and it shows in the horses gleaming state of health as well as in the healthy “countryside” aroma of their poo. In a nutshell, not all manure is equal and it pays to choose your source personally rather than rely on the A4 advert flapping on the entrance gate of the allotments. Try before you buy if it’s all possible and remember that among species there’s a hierarchy of value. My grandfather valued sheeps truckles above all else, but they’re better left on the land. I can’t imagine that he would feel the same about sheep muck from intensive farms where the sheep are fed on concentrates and never see a field.

Next comes the horse, but even then as I’ve already described, there’s a vast gulf between good and bad. If you’ve got loads of space it might be best to get it fresh, keep it covered and turn it yourself until it’s ready. Oh and check that they’re not worming the horses with some persistent vermifuge that will kill all your hard won worms. Cow’s manure comes last in the list and don’t ever use pig’s manure which is full of pathogens, and – if I haven’t already put you off – remember that e coli often comes as a freebie with manure, especially the fresh stuff, so keep it well away from salad crops and wash your hand carefully, perhaps with gel – like I did.

Good manure needs to be turned frequently to complete its decomposition and this obviously involves the farmer or stable in a lot of work which will be reflected in the price. Cheap is not always a bargain. So this pile of rather young manure which smelt strongly of ammonia was not all it was cracked up to be. But on the other hand we’ve had a tremendously wet winter and heaven knows how much nitrogen has been leached out of our soil during the past few months – so we’ll all be looking at organic ways of feeding it back.

What to do …?

Our allotmenteer has several choices to make. She could stack it and turn it regularly until it’s properly finished – which is extremely hard work. Leaving it as an uncovered pile will just mean more ammonia (nitrogen) escaping into the atmosphere as the weather warms up, while more will be washed away by the rain and could land up polluting the river. She can’t spread it among salad crops, tender plants or dig it into beds where she intends to grow root veg because they’re all adversely affected by fresh manure.

The one place I can think of where it would probably be OK is a good deep bean trench covered with soil. Another possible use is to use it in layers as a compost activator. She could mix it in layers with the free wood chip we have on the site which would reduce to compost reasonably quickly – the same would happen with dead autumn leaves because what this concentrated source of nitrogen needs is lots of carbon – even cardboard – to assist its decomposition and breakdown into “black gold“; odourless friable compost. Ideally she’d nurse it and turn it regularly and then spread it in the autumn and let the worms take it down.

There isn’t a 100% ram stamped ecologically pure way of composting – whether it’s manure or garden waste. The challenge isn’t to reduce wastage and greenhouse gases to zero – which I don’t believe is achievable – but to minimise it as far as possible. As Wendell Berry memorably said of intensive farming where manure is kept as slurry and cattle are kept in squalour, – they’ve taken a solution and turned it into two problems. Remember that in a small mixed farm where livestock are kept on grass, there isn’t – or shouldn’t be – any manure for sale at all because it’s just too valuable. Home compost made from vegetable material and activated with comfrey is as good as any animal manure you could get, unless it’s from your own livestock. The problem for small allotment holders is that we just don’t have space to grow comfrey and we don’t generate enough vegetable waste to compost our couple of hundred square yards sufficiently to compensate for what we take out. We too are intensive farmers! So beware of manure if it looks and smells like waste, because it probably is; and find a good source of safe horse manure and be prepared to put the work in. .