Introduction: water collecting,
Above, Above, an early use of a water collecting surface, in my lower growing area The plastic surface supplies a below-ground storage container. Also shown, a wooden composter I made, here with a corrugated PVC roof. A wooden roof is used when the composter is used for supporting winter squash plants, as shown below. On the left, two circular structures with netting for plant protection. To the right of the composter, tall runner bean plants supported by canes. Further information: my page on support systems. (Click for link.) The beds in front of the runner bean plants make use of the PHD support system for boards (click for link) which has substantial advantages. A pond now occupies the area to the left of the composter in the photograph above. It's very useful for water storage and for watering nearby plants and, of course, has other benefits - aesthetic benefits, and benefits to wildlife.
I store my longest ladder at my upper allotment. The area where the ladder is stored used to be a sea of mud in very wet weather - or at least a large patch of mud:
I extended the ladder and covered the area of the rungs with wooden boards:
After putting all the boards in place:
I covered the area taken up by the ladder and a further area, up to the two lines of vertical boards on either side of the ladder with sheets of 'Proplex' material, which is waterproof and very cheap. The water runs down the water-collecting surface and is collected in a storage container at the bottom of the structure, not shown here. The water storage container is a galvanized metal container bought at an agricultural supplies store. Before making necessary adjustments to the sheet to give a more tidy appearance:
The Proplex sheets can be removed, and replaced, very quickly. The path after removal of the sheets, with a flower bed to the left:
Above, the new PHD solar composter, one of the extensions to the greenhouse: a large composter, with polycarbonate sheets on all sides. On this side, the polycarbonate sheets are curved. (The sheets shown in this photograph have been replaced with longer sheets which now have greater curvature, giving greater interior volume.) These sheets, and the other sheets, bring about internal heating of the composter by the greenhouse effect, increasing the rate of microbial action whatever the external temperature, so that composting is faster and more likely to achieve the heating effect which kills weed seeds. The composter is a 'walk-in' structure: it has plenty of internal space so that the compost can be turned (with a manure fork) very easily.
Below, view into the interior of the composter, after removal of the door, which is made of flat polycarbonate sheeting. The compostable materials are covered with flat polycarbonate to increase insulation. Photograph taken 19.04.2020, a few days after the design idea, which was followed by very rapid construction. After completion, other gardening tasks, such as watering plants, had to take priority over accumulating more compostable materials to place in the composter.
Above, two photographs of the first composter I designed, in place for many years and still in place. A composting structure, like other gardening structures, should preferably have more than one function, if the supplementary functions don't compromise the primary function. This composter can be used for plant support whilst continuing to make compost. Below, the roof of the composter used to support winter squash plants:
The composter can be used for protected cropping, as a kind of cold frame. A simple supporting structure can be fitted inside the composter. It supports a growing container fairly near the upper surface. The plants growing here will benefit from the increased temperatures.. There's plenty of room for compostable materials below the supporting structure. This wooden composter can be converted into a solar composter. The wooden roof is replaced with a flat polycarbonate sheet or a corrugated PVC sheet.
There are TV programmes which pretend otherwise, but fruit and vegetable gardening on any scale, for any length of time, involves disappointment as well as fulfilment. 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 knotweed or some other weeds, pests - insect, bird, mammal, 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 unlkely that 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 marked. A large mass of compostable material gives not nearly as much compost as the gardener would like or the soil needs. To collect a large mass of compostable material in the first place is sometimes impossible, or requires so much effort. The end product is very desirable, but its contribution to soil fertility - the soil fertility of the whole growing area - could be viewed as 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 in most cases not to compost material which can be composted, or have the material which could be composted transported to a distant site. Composting has many more benefits than soil improvement, even if soil improvement is a central objective. All the same, 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 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. I'd describe myself as a dedicated composter in many respects. At the end of it all, the amount of compost produced is still unlikely to be massive, on the garden scale. 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 as well, perhaps - it's an absorbing interest for me - but no more than that - 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.
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. Although nettles are a much finer compostable material than hedge clippings, hedge clippings may well be obtainable in much greater masses than nettles - although nettles can be very prolific and useful contributors to composters.
As well as the composter above, I use composting systems which have a larger area than most of the ones commonly used, including hedge composting (there's also wall composting and fence composting). These techniques don't make use of a composing bin or a composting structure.
Another view of the large PHD solar composter, one of the extensions to the greenhouse. Making it cost me nothing. The curved polycarbonate sheets shown in the photograph to the right of the main greenhouse structure have been replaced with longer sheets, giving greater curvature and increasing the internal volume available for composting. These polycarbonate sheets were old sheets which I had available. The greenhouse offers great flexibility. This is one extension to the greenhouse. There are other extensions with very varied uses.
Looking into the interior of the composter a few days after the design idea and the construction of the composter. A small quantity of compostable material has been added. On the right, upright, the straight polycarbonate sheet which is placed over the compostable materials to increase insulation. This is a 'walk-in' composter. In most cases, the work will be done from just outside the composter. The large internal space allows easy mixing and rearrangement of the materials after the internal temperature of the materials has fallen. (I have a compost thermometer for measuring and monitoring the temperature in the interior of the materials.)
The fact that the walls of the composter are constructed from polycarbonate and the greenhouse walls are constructed from polycarbonate (and some corrugated PVC sheets) rather than glass makes working in close proximity to the walls safe. The partition wall between the composter and the main greenhouse structure accepts multiple layers of polycarbonate sheets. In constructing the composter, I used various old polycarbonate sheets to increase the insulation levels. Photograph taken 19.04.2020.
More material was soon added: nettles, climbing rose prunings and a layer of straw, which provided higher C material to make a more balanced C/N mixture.
Length (at all levels) 1.8 metre (5'11")
Width (at soil level) 0.9 metre (3') This is extendable.
Width (max.) 1.2 metre (3'11")
Height (max.) 2.0 metre (6'8")
This is the first solar composter I used, a much smaller one, using a
single curved polycarbonate sheet:
The rear 'wall' of the composter was a vigorous ivy hedge. The ivy made a contribution to compostable materials inside the composter, with good insulating value. Placing a composter next to a hedge makes constructing a composter easier and offers these further advantages. I dismantled the composter after the compost produced had been used for supplying some of the needs of two young rhubarb plants. I didn't carry out temperature measurements, using a compost thermometer, or make a methodical study of composting in this composter. The space taken up by the composter was now needed for the further growth of two trees on either side, a Bramley apple tree and a Dabinett cider apple tree. For a long time, I couldn't see any obvious site for a new solar composter but I've now found one - by converting one of the greenhouse extensions, I've made a much larger composter. This is a very recent project. I intend to make a methodical (or semi-methodical) study of composting in the composter, including temperature measurements. Given the demands on my time, the study is more likely to be semi-methodical.
The new solar composter is a 'walk-in' composter. It allows me to stand upright inside the composter and to work inside the composter if necessary. Usually, I will be working from just outside the composter but there's plenty of space outside the composter as well. This makes turning the compost and rearranging the compost material much easier.
Using the right tool saves a great deal of work in compost making, as in other gardening activities. In this case, the correct tool is a manure fork. 'The Organic Gardener's Handbook' by Margaret Elphinstone and Julia Langley' is excellent, and has a very informative chapter on tools. This is their section on the manure fork:
'The manure fork is related to the pitch-fork, designed to lift material and throw it or load it somewhere else. It is the most useful tool for building compost heaps. You can use it to load seaweed into sacks on the beach, to throw muck into a trailer, to mix up your weeds and grass mowings into a good compost ... It is a pleasant tool to use properly, because when rhythm and balance are right there is very little strain involved. You can shift a ton of manure with no aches to show for it, and work comfortably all day with it at a steady pace.
'Manure forks have four or five rounded prongs which curve upward, and the prongs are set at an angle to the shaft to assist the lifting movements for which it is intended. If you cannot find a manure fork at your garden suppliers, try an agricultural store.'
I have an alternative way of turning and mixing the compostable materials after the initial heating phase has come to an end, so that the heating effect can resume. The solar composter is at the boundary of this allotment. There's a sloping surface which leads to the lower allotment, trellis which can be covered with boards:
The materials can be transferred the short distance to the edge and allowed to fall into the lower allotment. When the materials fall, they are rearranged: dispersed and mixed. In the lower allotment, polycarbonate sheets can easily be erected to cover the compostable materials in the next phase of composting. When the compost has been produced, the polycarbonate sheets are removed and the compost can be used in the lower allotment and the polycar
Below, a privet hedge kept in check with material from below the hedge. Over a period of time, privet twigs, leaves, small branches were removed after hedge trimming and transferred to the bottom of the hedge. On the side shown here, the privet hedge is lower. On the other side, the hedge is much taller and the hedge trimmings were simply thrown over the hedge to this side. After partial breakdown, they were brought back to the near side and put on top of the privet hedge, as a check to the growth of the privet.
Rampant blackberry bushes at the bottom of the same allotment are being kept in check with different materials, mainly manure and straw. The manure from a local farmer is delivered and stored very near to this area, reducing the work of applying the manure. Part of the earthwork seen from above:
These are all forms of composting at a boundary. I use hedge composting in both the upper growing area and the lower growing area, in both cases near to a privet hedge. I use a long strip of land next to the hedge, about 035 m wide, as a long composting area. The hedge forms one of the long sides. The other long side is formed by boards supported by stakes, the system explained on the page beds and boards. This is a very flexible system. The boards can be moved very easily, for example nearer to the hedge or further away. When I work on beds near to the hedge, it's convenient to throw weeds and other suitable materials into this composting area by the side of the hedge rather than to take them to a compost bin or to put them in a wheelbarrow which then has to be wheeled to a compost bin. The materials are out of the way and if they're the least bit unsightly, grass or other things can be thrown on them to cover them up. The compost materials will play a part in hampering the sideways growth of the privet hedge. - these hedges grow outwards as well as upwards, of course. Whenever the hedge is trimmed, clippings fall onto the compost area, increasing the compostable material and avoiding the need to transport the clippings to a separate composter. Other boundaries, walls and fences, have similar benefits, except, of course, the benefits of restricting growth and the benefits of clippings, unless a fence supports climbing plants which are sometimes trimmed. I can't claim that this is an important source of compost, but it makes a contribution and it has a range of other benefits. Upward growth of one of the privet hedges is checked by a novel technique - using the top of the hedge as a growing bed! It retains most of the growing medium during a growing season. Since roofs are often used for growing, why not use the tops of hedges? I'm not a great admirer of privet.
View inside the greenhouse, showing some of the tomato plants, October 29, 2018. The courgette and squash plants, the runner bean and Borlotti bean and French bean plants were cleared a few days earlier, after harvesting the crop. The tomatoes had already been harvested and the time had come to clear the tomato plants. All these plants, of course, were placed in one or another composting area.
In previous years, I haven't used the greenhouse for growing crops during the winter. After spending so many hours during the warmer months, I've tended the outdoor winter crops, such as purple sprouting broccoli, but spent much more time on activities other than the tasks (or pleasures) associated with growing, such as updating the gardening pages of this site.
This year, I decided to retrieve compostable material and place it in the greenhouse, so that breakdown of the material could take place faster - not protected growing but protected composting. As the primary function of the beds is for growing tomatoes (I also grow a French bean or Borlotti bean plant in the summer months) then tomato plant residues are excluded. To add tomato plant residues to the soil inside the greenhouse would be mistaken. I don't need to obtain fresh soil for the greenhouse every three years, to avoid tomato plant diseases, as I grow grafted tomatoes in the beds (as well as non-grafted tomatoes in peat-free comost in containers.)
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.
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 fortunate, although it may take time to realize this. An overgrown hedge 5 metres or more high is a great asset. Placing a composter near to a hedge like this is often a good idea, or composting near to it without using a composter.
I've made extensive use of twigs and the smaller branches from nearby hedges to extend the growing area: 'bed-extension.' This is a form of composting. The twigs and branches form an open network, allowing weeds to continue growing for some time (the weeds include grasses, and not just 'weed-grasses' such as couch grass.) The weeds contribute nitrogen, helping to offset the woody twigs and branches, which are high in carbon. I place a thick layer of manure over the twigs, preferably manure in clods or coarse pieces, which will remain on top of the twigs and branches and not fall through. Some of the nitrogen in the manure is washed away to the deeper level and helps to speed up the breakdown of woody material. In less than a year, crops can be grown in the area, although not crops such as carrots, which are harmed by manure. Soil is spread on the manure before planting. Only a thin layer is needed.
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, if they are unobtainable. In time, the hedge cuttings will form good compost, even if, as always, there isn't enough of it. 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.
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 on the page 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:
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 later in autumn.
Since the photograph was taken, I've added a thick layer of manure and a thin layer of soil and the bed is now available for planting. Without an enormous amount of effort, a large bed has been created. I've followed the same procedure to make a second, smaller growing bed.
When possible, composting should 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, or the weed-infested ground which will be converted to a growing bed. A compost bin can often be placed 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. There are any number of other activities which can be carried out in the time saved.
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:
Recycling plastic uses large amounts of energy. This energy cost has to be set against the environmental benefits of breaking down kitchen or garden waste into compost in a plastic bin. The resources a plastic container wastes can be considered more significant than the ones it saves.
Unlike metal or glass, which can be recycled many times, plastic in general can only be recycled once, due to contaminants. It's very probable that the plastic will end up in a landfill site sooner or later.
Plastic is discordant in a garden or allotment, a synthetic material at odds with organic life. It's far better to restrict its use to things such as water butts where plastic is obviously the best material to use.
Wooden bins are far more flexible than plastic bins, and can offer better insulation when they are placed next to each other. Three wooden bins can be placed in contact, giving the same benefits for heat insulation as three terraced houses in a row, which insulate each other. Three plastic bins are only available separately (although it would be quite easy to manufacture a set of three adjoining plastic bins) and have the same disadvantages for heat insulation as three detached houses. If a large amount of composting material becomes available, the volume of a plastic container can't be increased to take all the material.
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.
This is an improved wooden composter. One advantage is that it can be placed on sloping ground.
The upper surface of the composter can be of varied materials. The version shown in the image towards the top of the page has an upper surface made of wood. This can be replaced with a PVC top. It can be used for rainwater collection, if the composter is on sloping ground - the slope may be a very gentle one. It also increases the temperature inside the composter. The greenhouse effect increases the temperature inside polytunnels and cloches as well as greenhouses, but it can also be used to increase the temperature inside a composter. The biological processes which produce compost are speeded up and the compost is made in less time. When the composter is empty - and when the composter is almost full - materials for composting can be grown inside the composter to make a contribution to the common problem, lack of compostable materials, and the PVC panel enables them to be grown more quickly.
The composter is solidly constructed and large but it can be moved from place to place without difficulty, after it has been dismantled. (When I constructed a solid and large workbench for my workshop, I designed it to be easily moved. The bench can be raised using a hydraulic jack, castors can then be fitted and the bench can be moved from place to place. Alternatively, the bench can easily be dismantled and the separate parts taken to a different location and reassembled.)
Other aspects of composting
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.'