Introduction: composting
Obtaining compostable material
Disadvantages
of plastic composters
Disadvantages
of traditional wooden composters
The
'low-level composter'
Turning the heap Other aspects
of composting
Rainwater collecting: introduction
Rainwater collecting: using paths
Rainwater collecting: a raised reservoir / pond
Gardening photographs 1
Gardening photographs 2
Bed and board
Plant-protection cages with flexible supports
Cloches, cheap and simple to make
Transframe, a system with many uses
Some design principles in gardening
There are TV programmes on the subject which pretend otherwise (I don't have a television, but I've seen something of their dishonesty), but fruit and vegetable gardening on any scale, for any length of time, involves disappointment as well as fulfilment. Reality quickly sorts out or discourages for good any dilettantes who hope to carry away armfuls or trugfuls of beautiful fruit and vegetables in no time at all with minimal work and study. (The importance of knowledge as well as hard work should be stressed.)
The harsh realities come in many different forms: weeds, the worst of which can seem like one of nature's bad jokes, although it would be difficult to see the funny side of Japanese, giant or hybrid knotweed or some other weeds, pests - insect, bird, mammal and human (allotment vandals included here in the category of pest), plant diseases, pests which spread plant diseases such as aphids, weeds which are the hosts of disease-causing organisms (yet another disadvantage of weeds), watering in times of drought, the time-consuming watering which isn't just a token gesture but enough to satisfy the voracious thirst of potatoes and other crops and ensure a good yield (subject to potato blight and perhaps other diseases), the difficulty of obtaining a good yield.
Even if most things go well (it's impossible for all things to go well - if temperatures are right and rainfall is just right, not too much, not too little, things are going well for the weeds as well) then there can still seem a disproportion between effort and yield. Some crops are markedly superior to others in this regard. Runner beans give a better yield than broad beans, courgettes give a better yield than peas.
Composting gives a low yield. The disproportion between effort and yield is very marked. A huge mass of compostable material gives not nearly as much compost as the gardener would like or the soil needs. To collect a huge mass of compostable material in the first place is very often impossible, or requires great effort. The end product is very desirable, but its contribution to soil fertility is more peripheral than central. In economics, there's a great gulf which is often cited, the gulf between infinite wants and scarce resources. In gardening, there's a gulf between the needs of the soil and the scarce resources of compost.
Every gardener should compost - it would be a breach of gardening ethics to throw it away, or have the material which could be composted transported to a distant site, in most circumstances - but a gardener has to be careful not to give too much effort to composting at the expense of other gardening tasks, and non-gardening tasks and duties, for that matter.
There are many dedicated composters, as well as fanatical composters, who devote great effort to securing diverse materials to build a well-balanced heap and who turn the heap to ensure that the heating effect continues. At the end of it all, the compost they produce is still a marginal product. Manure, unlike compost, is generally obtainable in large mass and makes correspondingly greater contributions to soil structure and soil fertility, despite the lower concentration of plant nutrients in manure. Composting should be viewed as a gardener's duty, an absorbing interest or hobby as well, perhaps, but no more than that, and certainly not the semi-sacred preoccupation of some organic gardeners.
My discussion here is in accordance with this thinking. I discuss ways of increasing the supply of compostable materials and ways of saving work - the work of bulk handling, when compostable materials are available in quantity, and work once the composting process is under way. I also discuss compost containers - plastic, traditional wooden, and the composters I use myself, designed to minimize the effort in producing compost: this valuable material, but one whose worth can easily be exaggerated. Unlike other sections of this gardening section, there are no innovations here.
So far as possible, composting should be integrated - unobtrusively, as I see it - into the other aspects of gardening. I discuss some gardening techniques which have a linkage with composting, such as hedge-cutting and weed clearing. Athough nettles are a much finer compostable material than hedge clippings, hedge clippings are almost always obtainable in much greater masses than nettles. I advocate composters which have a larger area than most of the ones commonly used, allowing a greater area of growing weeds to be covered. The weeds continue to grow for some time as compostable material is added and the weeds contribute more compostable material, although not in substantial amounts.
One of the most important principles of sane composting is that composting should so far as possible be in situ, or not at a great distance from the compostable materials. Bulky compostable materials should so far as possible be composted near to the supply of bulky compostable materials. Composting can often be carried out at the place where compost will be needed - composting on the growing bed. Growing areas of any size should have a number of composters, to minimize transportation distances. There are any number of other activities which can be carried out in the time saved.
To begin with, I emphasize the well-known fact that cooked food, bread, cheese, anything that omnivorous rats can eat, should never be regarded as compostable.
Often, plastic compost bins are seen in very small gardens. Unless someone has large amounts of compostable material from other sources - and not in the least distant sources - then a plastic compost bin is wasteful. The resources it wastes are far greater than the ones it saves.
Even a large allotment or garden produces a very modest supply of compostable material, and even in autumn, when such plants as runner bean, courgette and tomato are generally available for composting.
Anyone who takes on an overgrown, neglected garden or allotment is very fortunate, although it may take time to realize this. An overgrown hedge 5 metres or more high is a great asset. So too, despite their much lesser mass, are greath swathes of nettles and other weeds. The composter can be at some distance from the nettles and other weeds but it should be as near to the hedge as possible.
Books and articles often stress the need for a mixture of materials, giving a good balance of textures and a suitable ration of nitrogen to carbon. What they don't stress is the disproportionate effort often needed to ensure this, the difficulty of obtaining sufficient of these varied and contrasting materials. A compost heap made up almost entirely of hedge cuttings, high in carbon, with a very open texture, despite the leaves, is well worth having and certainly much better than nothing. There's no need to worry unduly, or at all, about bringing up materials with a less open texture, with a greater concentration of nitrogen. In time, the hedge cuttings will form good compost, even if, as always,there isn't enough of it.
A powered hedge cutter or shears can be used for mildly overgrown hedges, but for grossly overgrown hedges, I've used a different tool, a small hand-saw and loppers. I use loppers to detach many of the smaller branches, giving access to the larger branches, which I saw away. Before very long, a grossly overgrown hedge has been reduced to a short, very bare-looking one, which will, however, revert to its previous size if allowed. A powered brush cutter or chain saw can avoid some but not all of this work.
During the season when the pictures at Photographs 2 were taken, I spent a very great deal of time constructing the wooden paths, designing and constructing the raised pond and composters shown on the right, designing and constructing transframe, and on all the other work of the allotments - and, amongst other things, watching the flight of swifts. There was no time to see to the privet hedges, which grew to a great height. When I did cut them to a fraction of their overgrown size, I piled up the cut material -
season This is an area which, like the area occupied now by the raised pond and composters, and adjoining it, was obviously used as a dumping ground at some time in the past. Plastic, glass and metal were visible. The soil was only of an adequate depth in one very restricted area, where I planted an apple tree, just visible, with its supporting stake, in the photograph above, taken in later autumn.
Lawrence D Hills claims (in his classic but flawed and outdated book 'Organic Gardening') that hedge cuttings thicker than a pencil won't decay in a compost heap. This isn't true, of course - given enough time, all wood will decay, whatever the size - but it's a good rule for the short term. Compost will be formed from most of the material here within 2 or 3 years. The compost will be sufficient to transform the dumping ground and with the addition of manure and soil which can be spared from other areas, shallow-rooting crops at least can be grown here.
The nettles and other weeds in a neglected garden or allotment can be used as compostable materials by dedicated or fanatical composters but the effort is disproportionate. It's better to put weed-control fabric on them and increase nutrients in the soil and improve soil texture in this way. Even so, it's well worth while to place a compost bin if possible on a particularly rampant area of weeds. They will continue growing for quite some time and well benefit the mix of compost materials, without any effort in cutting and transporting them.
Plastic is generally the best material to use for a water butt - making a watertight wooden container isn't an easy matter - but not at all the best material to use for a compost bin, even when the plastic is recycled. There are various objections to the use of plastic compost bins:
I used a Rotol plastic composter for a time, many years ago. It can produce very good compost and the design has undeniable appeal - a conical shape which looks very good. For all that, the Rotol has the disadvantages of other plastic composters. The top diameter is 45cm and through this fairly small opening all the compostable material has to be inserted (after being lifted up to a height of around 75cm.) The Rotol composter is made of unrecycled plastic.
Composters, then, if at all possible, should be made from a renewable resource, wood, and if it can be obtained, reclaimed wood.
Even though wood is the best material to use for a composter, the traditional wooden bin has disadvantages:
Edging boards, supplied in this country by Grange, provide a very quick and convenient way of making a composter. (See photo at top of page.) The capacity of the bin is much greater than would be expected. If the material inside is level with the top of the wood, the composter holds 315 litres, but more if the material is heaped up. The material inside will subside later. Many manufactured composters hold only about 200 litres. The cost of four edging boards is roughly 25.00, correspondingly less if two or three are bought. This compares favourably with the plastic composters in the 'Organic Gardening Catalogue' which cost 59.95 and 43.95 but have less capacity, or with the wooden compost bin which holds 600 litres but costs 85.75. This composter is put together in a matter of moments and other units can be added just as easily.
This low-level composter has the advantage that it's just the right height to allow the contents of a wheelbarrow to be tipped into the composting area, and from any available side. However, the higher sides of the standard composter can be removed so quickly that wheelbarrow loads can be added perfectly easily, until the compostable material reaches a certain height.
The Centre for Alternative Technology factsheet on Cool Composting states that in composting, 'better results are obtained with containers that are:
This low composter qualifies on all three grounds.
The Centre for Alternative Technology's Factsheet is completely realistic in stating that very few people turn the compost heap, even if they have gone to the trouble of forming a heap which has heated in the first place. The heap is turned - if at all - after the temperature has reached a maximum and has then begun to fall. This is because moving such a heavy load deters almost all but physically strong and very committed people.
I don't deal here with large-scale composting, the composting systems needed if compost is to be sold, the composting systems subject to legislation, the composting systems which require an energy input (such as the composting systems produced by Accelerated Compost Ltd) with in-vessel composting systems in general.
The advantages of the restrictions? The advantages of composting in the garden or allotment, rather than sending the material to an in-vessel composting system, are very substantial ones. Compostable materials are mainly water, and transporting heavy masses of water - along with the valuable organic matter - may make economic and environmental sense, or it may not. Not if the distance is great. Like paper recycling, organic waste recycling can have great benefits, negligible benefits or no benefits at all, and one of the most important considerations is the distance the compostable material has to travel - the 'composting miles.' The reason is to do with use of fossil fuel, of course. In situ composting, composting in the garden or allotment, has the advantage of composting distances amounting to yards not miles.
Another advantage of in situ composting is the benefit to wildlife, unless the composter is a closed vessel, such as a compost tumbler. The composter as a valuable wildlife habitat is often overlooked, but Ken Thompson's very lively, very interesting and very informative book 'No Nettles Required: the reassuring truth about wildlife gardening' outlines the advantages to wildlife. Ken Thompson is a researcher at Sheffield University and his book gives some of the findings of the 'BUGS project.' BUGS stands for 'Biodiversity in Urban Gardens in Sheffield.' The project was supported by the major government funder of environmental research, the Natural Environment Research Council.
Of compost heaps, he writes (Page 76, 77): 'Unfortunately, the BUGS project had neither the time nor the money to look at compost heaps in detail, but other research (much of it from Scandinavia) reveals that compost heaps are hugely important wildlife habitats in their own right. This is because warm, decaying plant material is a habitat that would otherwise be absent from gardens. Reptiles in particular like these conditions, and a survey in Bristol found that gardens with compost heaps were twice as likely to have resident slow worms as those without compost heaps. Given the appetite of slow worms for slugs, this has to be another good reason for starting a compost heap...compost heaps go a long way towards replacing a whole catalogue of wildlife habitats that would otherwise be rare or absent from gardens, and are increasingly rare in the wider countryside. Another interesting feature of compost heaps is that by providing a warm, insulated habitat, they allow many species to spread further north than they would otherwise do. Many native species live further north in compost than in any other habitat...' And, in a summary box: 'Compost heaps are...a uniquely valuable wildlife habitat...No gardener with any interest in wildlife should be without one, however lacking you may be in the raw materials.'
Techniques and equipment which don't work or which require an effort completely disproportionate to the results should be abandoned or modified or at least recognized for what they are: token gestures. An example: water butts, intended to make a contribution to water collecting. Their contribution is negligible. This is for the obvious reason that the collecting area is very small. For a water butt with a diameter at the top of 0.4 m (there are many water butts with smaller diameters than this), the collecting area is only about 0.12 square metres. In general, even five water butts will collect a negligible proportion of the rainwater which falls on a growing area and will make a negligible contribution to satisfying the demand for water. Virtuous feelings of contributing to 'conservation of resources' aren't sufficient justification.
Water butts are most useful for storing water which has been supplied by a tap - if, of course, a mains water supply is available. There's a water tap near to my allotments, but the supply of water has sometimes been interrupted and this has happened in spring, during a period of extended drought, when I was planting asparagus and other crops, I used up all the water in the large tank which stores water collected from the greenhouse roof, which holds 1 000 litres (a tonne of water) and after that, my only supply of water came from the small pond in the upper allotment. Since then, I've extended the facilities for water collection and storage in the ways I describe here. If gardeners in this country can't take for granted an assured supply of mains water and adequate rainfall, gardeners in arid climates face much greater difficulties, of course. It's possible to collect only a proportion of the rainwater which falls on a growing area or an area near to the growing area. It's obviously not possible to make the whole of a growing area into a collecting area, but it's necessary to have available collecting areas much larger than the collecting area of a water butt, or a number of water butts. I use paths and reservoirs to collect water.
The photograph shows a water butt in my lower allotment. The photo was taken at a time when no growing area looks its best, in January, in very mild weather. (A large area of this allotment was under cultivation at that time: over-wintering broad beans, visible in the photograph above, onions, purple-sprouting broccoli and kale.)
The water butt collects a little water but its main use is to store water from a much larger collecting area. (The wooden structure in front of the water butt is a transframe, shown here with only a PVC top-panel, no side-panels. The PVC top panel can be fitted with a section of guttering and can be used for water collection too.) The two principal hard surfaces shown in the photograph are the two paths constructed from wooden boards, with raised wooden edging. I've laid down heavy-duty plastic sheet material on the path on the left and covered it with netting (not clearly visible in the photograph) so that it's possible to walk on the path without slipping. The rainwater which falls on the path runs down into a container at the bottom of the path, buried in the soil. A wooden board covers the container. Containers of very large capacity are obtainable which can be buried in the soil, but the container here is much smaller. At intervals, I pump the water from the buried container into the water butt, using the hand pump leaning against the water butt (a very well designed pump manufactured, as it happens, in Samoa.) The pump can be used to pump water to growing areas or other water storage containers uphill. Alternatively, a watering can can be submerged in the small container. This is often a convenient way of using the water.
This method of collecting water wouldn't be possible in the case of a path which is on level ground, but the slope needn't be at all steep. Paths on gently sloping ground can be used for water collection.
The system shown can be regarded as a prototype, but the only improvements needed are to do with appearance, not functionality. The system works perfectly, and the volume of water collected is substantial - given a modicum of rainfall, of course.
More recently, I've developed techniques, not described here, for rainwater collection which don't require the conversion of paths.
The next two photographs show another large water collecting surface, a reservoir. The red object in the second photograph here shows the hand water-pump I use.
The reservoir is shown in early autumn in the image near the top of this page, with composters on either side (the second photograph from the top.) The two images here show the reservoir in January. I've converted the compost containers into growing beds by adding soil and manure to the compost. This bulky material on either side of the reservoir withstands the pressure exerted by the water in the reservoir. There are supporting structures hidden from view but these are cheap and simple to make. Their role is to support and keep level the rectangular edging of the reservoir. The reservoir can be constructed on sloping as well as level ground - the ground here is sloping and uneven - and doesn't require a wall as the boundary on one side. It can be constructed anywhere in a growing area, in fact.
The wall here is south facing, so this is a very favourable situation for growing, but the soil in this area is very thin. Beneath it is a deep accumulation of rubbish which must have been deposited a long time ago - broken glass, rusting metal and plastic. The beds on either side of the pond allow crops to be grown here now.
The reservoir is functional. A primary function is collection of rainwater which can be used to irrigate crops, using the handpump, water syphoned from the reservoir or a watering can. It would also be possible to add an overflow system which includes piping. It's intended, though, to be more than functional, a pond So, one of the things I've planted in the pond is the native white water lily, Nymphaea alba (dormant at this time of year, of course). The rectangles of soil and water form an effective contrast, I think.
This shows the areas of the water-collecting surfaces in my allotments in square metres.
water butt 0.4
small pond 0.7
PVC top-panel of transframe 1.5
reservoir 2.7
water-collecting path 6.3
greenhouse 36.5
The greenhouse is a comparatively large one, over 11 metres long. Growing areas are water collecting areas as well, of course, but not the growing area inside the greenhouse. The large contribution to water collecting made by the greenhouse roof is subject to this {restriction}, then: not all the water collected by the greenhouse roof can be used in other areas.
The water collecting path is narrow. Adding a water collecting surface
to the wider and longer curved path to the right would increase the water
collecting surface significantly. The method used for a straight path has to
be modified for a curved path but is straightforward to implement.