To quote the advice of Arthur Fallowfield – the wonderful invention of comedian Kenneth Williams, “The answer lies in the soil”. It always does, but he was spoofing the whole organic gardening movement in its tweedy 1930’s incarnation. I am aware, of course, that the gag will completely pass over the head of anyone under retirement age but I remember the tremulous plummy voice that seemed to spring straight from the pages of “Cold Comfort Farm” – dripping with the husky erotic overtones of flowering sukebind.
Last autumn, when I built the compost bins I was doubtful if we’d ever be able to fill them, even with the green kitchen waste included. Each bay is approaching two cubic metres in size, and there are four of them – and I was right to be dubious. One of the bins has been used ever since to store leaves, and should provide at least a cubic metre of leaf mould every year. One bin has been used for storage of bags of consumables like bought-in compost, topsoil and grit, and I’ve built removable shelves over both of those bays to make use of the upper area for growing in bags. But the other two bays have shown that they are well up to providing a constant supply of compost. They’ve only been up for less than a year and we’ve already taken off two cycles, maybe ten heaped barrow loads of really good compost.
Previously we’d always used California cylinders which are portable, cheap and easy to make but almost impossible to turn. The hope was that having permanent wooden bays would make turning easier -which has turned out to be true, and because it’s easier I turn the heap more often, which keeps it sweet and hot and remarkably efficient at reducing the most intractable waste into compost. Woody waste is chopped into small pieces and cabbage stumps get smashed with the back of an axe, but even soft fruit prunings disappear. The only things we don’t compost are noxious perennial weeds and annual weeds that have set seed. We’ve also learned that as well as regular turning, the heap responds well to a surprising quantity of cardboard (as long as it doesn’t have a plastic finish). The one thing you never find in a finished heap is cardboard – it seems to disappear really quickly and we often supplement our own household cardboard waste with shredded paper and large boxes from the recycling containers in the basement. The worms also love it although they don’t seem to eat it, they tend to congregate around it. Finally the heap gets a regular soaking of urine and the odd layer of comfrey if I can find any; or a handful of organic fertilizer or seaweed meal now and again. The one thing you can’t do is just leave it uncovered for months. It’s far better to keep it covered and water it when it looks dry, than it is to allow it to get cold and wet. Are you getting the picture? Composting is an intense and interventionist activity.
So today was heap turning day because we’ve cleared a couple of beds and the plan is always to clear them, compost them, and then sow or replant them as quickly as possible. Allotmenteering is pretty intensive all round, and digging out a full bay is hard work because in our case our optimistic use of “biodegradable plastics” – Jiffy 7 modules and degradable kitchen waste bags in particular has taught us that they are rarely broken down and can persist for years. So we’ve been removing them – hundreds of them – as the finished compost is dug and put through a wire riddle. It’s slow but very rewarding work as lumpy garden waste emerges from the process as sweet smelling friable and fine grained compost, inoculated with worm casts – in fact almost all of it seems to have passed through worms at some point making it vastly more valuable than bought in compost. There was enough today to cover two 12’x 5′ beds to a depth of 3″ and fill two large planters – and enough pieces of plastic to fill a large bag! After riddling and taking out the plastic, any hard residue, bits of twig etc. go back to the bottom of the new heap.
Turning the active heap which was full to the brim was a bit more of a performance, not least because I came across a very large rat and was forced to engage in hand to hand combat with it for fear of getting bitten. I once had a rat jump over my shoulder and I’m not sure which of us was more terrified! Rats are a tremendous nuisance but it’s hardly surprising that they congregate around compost bins which provide food, warmth and shelter. The problem is that they’re also carriers of leptospirosis which is transmitted through their urine, and so we really don’t want them leaving their traces on crops, particularly those like salad greens that are eaten raw. They also ruin sweetcorn crops because – like badgers and deer – they love the sweetness. We try as best we can to exclude them but they’re great climbers and even if the bins themselves are rat-proof, they can easily climb the sides and get in through the top and so they’re a regrettable pest and although I hate despatching them they come under the same banner as slugs. And so if we can, we kill them with powerful spring traps designed to keep out other less harmful species and occasionally I have to do the job myself because they soon learn to recognise the traps and even manage to eat all the peanut butter bait without springing them. We don’t use poisons of any kind because that just displaces the moral responsibility by making the consequences invisible.
But aside from the pests, what about the friendly inhabitants of the compost heap? I’m constantly amazed at where the brandling worms come from. We’ve never gone to any trouble, they just emerge from somewhere and in a lively heap they multiply exponentially. There’s a paradox here because there’s more than one process going on in a heap. The bacterial process is stage one, and it’s the foundation for the worms’ work. All the feeding with water, urine (human not rats!) comfrey and carbon in the form of cardboard facilitates the initial stages where the heap warms up. Many enthusiastic bloggers will make great play of the maximum temperatures in their heaps and some will claim that they reach quite extraordinary heights. We much prefer to leave the heap to heat up to – say – 30C in the initial stages. Bacteria, insects and worms all have their comfortable temperature ranges, and it doesn’t make much sense to me to drive all the invertebrates out by having the heap too hot.
In practice, the brandling move around – to the cooler edges when the heap is heating and then back to the centre when it cools and they can begin their vital work of digesting the partially rotted waste and turning it into worm casts which are absolutely crammed with soil improving bacteria. Well made garden compost and cheap garden centre compost are worlds apart. When the worms have done their work the population declines and they move elsewhere – which means it’s time to dig the compost out and spread it thickly on the plot.
Yesterday as I was digging out the finished compost, it was clear that there were far less brandling than in the ‘live’ bin, but as I dug deeper I was finding more of the deeper soil dwelling earthworms. It’s wonderful to watch how the process constantly balances itself. And worms aren’t the only inhabitants – it’s teeming with invertebrate life all chewing their way through our waste and turning it into gold, and I don’t doubt that the inhabitants get smaller and smaller in a massive interconnected ecosystem – it takes your breath away.
The result of building up the soil with organic matter is increased fertility, increased yields, greater biodiversity and healthier plants. It’s a no-brainer. Of course you can increase yields by pouring on artificial fertilizer year after year, but as the biodiversity drops the intractable pests increase and you find yourself trapped in an expensive and depressing spiral of feeding and spraying. But here are some photos of the allotment taken yesterday, and hopefully they speak for themselves.