What is organic gardening?

These days, gardening is a multi-million pound industry, complete with professional designers, exotic plants and huge retail warehouses. And although the philosophy which underpins the organic alternative was developed before the days of garden centres, extreme makeovers and celebrities in green wellies, it is, in some ways, the antidote to them. This is because rather than relying on plants, fertilizers and hard landscaping imported from all over the globe, the organic model emphasizes recycling and reusing as much as possible of what your garden already produces in order to maintain healthy soil and a thriving local ecosystem. On the whole, it does not encourage exotic planting, but promotes instead the use of local varieties and cultivars which are adapted to your particular conditions. For these reasons, maybe a better name would be 'sustainable gardening'.

At the heart of all every organic garden is a well-nurtured soil. Bursting with life and full to the brim with every kind of soil-dwelling organism from microscopic bacteria to larger invertebrates such as worms, it will support a system of natural pest control from aphid-munching ladybirds to slug and snail eaters like thrushes and hedgehogs. With allies like these at your disposal, it will be much easier to achieve your goal of gardening without chemical insecticides.

If you want to learn about organic gardening in more detail, you couldn't do better than to visit the website of Garden Organic (formerly Henry Doubleday Research Association) at www.gardenorganic.org.uk. This is a registered charity which exists to promote and research organic horticulture in the UK, as well as to educate both novice and experienced gardeners about the benefits of gardening organically. While I can't hope to better anything Garden Organic has to say, here are some basic rules of organic gardening, together with the rationale behind them, and brief descriptions of some of the problems you might encounter when trying to follow them.

• Feed your soil. This is arguably the most important article of faith in the whole organic canon. As I indicated above, a healthy soil, rich in organic material (and in this context I am using the word 'organic' to mean 'material derived from living organisms', rather than the narrower meaning implied by the term 'organic gardening') is the key to supporting a vigorous local ecosystem which will in itself go a long way towards providing you with natural pest control. Organic material in your soil is also a source of nutrients for plants, and will help dry soils to retain moisture. On wet soils, paradoxically, it will improve drainage!

  If you want to add organic matter to your soil, you have three options. The first is to add garden compost, which you can make yourself from garden wastes. I'm an enthusiastic composter, and would recommend that you become one too, but I'm not going to spend time here telling you how to go about it, because you can find out everything you need to know on the Garden Organic website. My only complaint about compost is that you can never, ever make enough of the damn stuff - I seem to remember that Monty Don came up with mathematical proof of this in one of his Observer columns a few years ago. Leaf mould is anther good soil conditioner - but it's difficult to make enough of that, either.

  Your second option is the age-old tradition of adding farmyard (usually cow) manure to your soil. Unless you live on a farm, you're unlikely to be able to produce your own supplies, so it could be argued that its use is incompatible with the idea of the 'sustainable garden'. It can be also be difficult to get hold of, and some gardeners are wary of using horse manure in particular, because it may contain residues of worming tablets. It certainly contains a lot of weed seeds. Manure from organic farms is almost never available, because organic farmers recycle their manure back onto their own land. Happily, the advice from the Soil Association (the main UK body for certifying organic produce) is that manure which has been left to stand for six months will have broken down any nasties, and can be regarded as acceptable to organic practice.

  Vegan organic gardening is a further refinement of the organic approach. It eschews the use of all animal by-products in the garden, including manure, on the grounds that their use implies acquiescence in the animal suffering which, it is claimed, is inherent in our system of raising animals for human consumption. Whether or not you agree with this viewpoint is something you will have to decide for yourself. In the meantime, anyone interested in finding out more about vegan organics can do so at the Vegan Organic Network's website, www.veganorganic.net. Gardeners who continue to use animal products can salve their consciences to some extent by reading Colin Tudge's book So Shall We Reap (Allen Lane, 2003), which makes a sane and balanced plea for the ecological and economic benefits of mixed farming.

  The third major way of enriching your soil with organic material is to grow, and then dig in, green manures. Green manures are useful in any garden, but form a particularly valuable adjunct to compost in a vegan-organic regime. Your only problem, in a busy and productive allotment, might be finding room to grow them on a large enough scale! Green manures are typically fast-growing plants which quickly produce a mass of weed-suppressing foliage. They are not usually used for food, although some, such as phacelia, have pretty flowers which act as insect attractants. How do they work? Well, some have penetrating roots which bring nutrients from deep in the soil back up to the surface; others are members of the legume family, which fix nitrogen in their roots. All green manures, once their top growth is dug into the soil (or just cut down and left to rot on top) will provide valuable humus.

• Don't use artificial pesticides or herbicides. Organic gardeners do not use artificial pesticides, herbicides or fertilizers because they believe that they impoverish the soil, disrupt the local ecosystem and can be toxic to human and non-human life. The few pesticides which are approved for use in organic systems are based on naturally-occurring chemicals and should be used only as a last resort. Instead of chemicals, organic gardeners rely for pest control on the encouragement of natural predators and on different kinds of traps and barriers which prevent the pests from reaching the crops in the first place.

  Organic gardening has been criticized in the past for being too arbitrary about which chemicals it allows and which it does not. It is argued that plants, edible ones included, naturally produce thousands of chemicals, many of which are still poorly understood, and some of which are toxic. With the garden already bursting with naturally occurring chemicals, supporters of this view contend that it's pointless to worry about adding a few extra ones to the mix. Their argument is bolstered by the fact that compared with the horrors of the past, the list of chemicals approved by the EU for back garden use seems relatively benign - so is our continued reliance on them really such a big deal? Well yes, actually it is. The use of pesticides and herbicides wipes out valuable sources of bird and animal food; and as no chemical can be tested on every single life-form, they may still be highly toxic if used in ways that were not foreseen, or if ingested by species whose exposure to them was not considered when they were tested. It is also true that in the average British garden they are rarely, if ever, really necessary. When so many alternative methods of control are available, it's high time we asked why we are still using them.

  But it isn't just about chemicals. Sustainable gardening is about thinking through the impact of everything we use on the planet as a whole. Take plastic: most organic gardens are full of the stuff. And yes, I can hear gardeners all over the land shrieking "but I re-use it over and over and it lasts for years!" and I don't doubt their sincerity. But plastic is still a material which is notoriously problematic to dispose of: it won't biodegrade, it releases toxins when burnt, and can be difficult to recycle. It's also made from oil, a precious non-renewable resource. Likewise, 'organic' garden sundries have come in for criticism from some writers on the grounds that they are produced in ways that are far from sustainable. In an article called 'Animal, vegetable or mineral?' (Organic Gardening Magazine.12,11, Nov 1999), Paul Hending asserts that calcified seaweed, an approved organic plant food, is produced by dredging the seabed off the coast of Brittany, causing untold damage to aquatic life there^[1]. Dolomitic limestone, another approved organic sundry, is, he says, simply mined with diggers in north-east England.

  While I don't suggest that anyone stop using any of this stuff immediately, or at all, it demonstrates the necessity of careful thinking. Unquestioning adherence to rules, just because they are rules, can produce illogical results.

• Don't use virgin peat. This is vitally important because the habitat destruction caused by peat mining is catastrophic. In Britain, extraction has now ceased in some of the most environmentally sensitive areas - good news for us, but bad news for the ecosystems of other countries which have stepped up production to meet continuing demand from the British market. Worst hit has been Estonia, where some of the last refuges of rare wildlife such as the European brown bear and the great grey owl are under threat.

  The problem with not using peat is that you have to use something else instead. Many alternatives are on the market, including council green waste, composted bark and coir (a coconut derivative). If you have the time and space, you can also try what is probably the most environmentally friendly approach of all: making your own composts from ingredients such as leafmould, garden compost, loam, sand and manure. Unfortunately, whichever one you choose, you are likely to run up against the same problem: they are not as good as peat. They either dry out too quickly (coir), are full of lumps (composted bark) or they simply don't provide the level of nutrients that young plants need (something I found when growing brassicas in home made compost).

  My own solution to this problem has been to carry on using simple home made mixtures for raising large-seeded plants like peas, beans and squashes - I have to raise them in modules because mice eat them if I direct-sow. These seeds contain so much food for the young plant that they don't need the additional luxury of rich compost. For brassicas, which need plenty of nourishment, I splash out on Moorland Gold, a non-mined peat available from the Organic Gardening Catalogue. Its drawback is that it's very expensive, which is why I restrict its use to plants that really need it.

• Use local, and if possible, recycled materials for hard landscaping. In a sustainable régime, the logic of this speaks for itself really. In particular, pressure treated wood should be avoided because of concerns that under certain conditions it may leech toxins into the surrounding environment. Organic gardeners also tend to prefer builders' lime to cement because of the high energy use and very poor emissions record associated with cement manufacture.

Footnotes

[1]

Chase Organics, the company behind the Organic Gardening Catalogue, has gone on record as saying that the raw material for its seaweed meal comes from a sustainably-harvested source on the West coast of Ireland.

Why garden organically?

There are so many reasons to garden organically that it actually makes more sense to turn the question around and ask: Why garden chemically? But here, if you need them, are five good reasons for switching to an organic approach.

For taste

To be honest, when you’re trying to win over the sceptics, this is probably not your trump card, at least as far as fruit and veg are concerned (meat is rather different).Taste is subjective, and for every celebrity chef who waxes lyrical about the fantastic taste of organic food, there are plenty of people ready to swear it tastes no different from conventionally-grown stuff. What is indisputable is that fresh produce, picked at the peak of ripeness and used within hours if not less, tastes better than anything you can buy at the shops. If you don’t believe this, try comparing a freshly picked home-grown strawberry with an imported out-of-season example of the same fruit. Remember that supermarkets select the varieties of strawberry they sell not on the basis of taste, but on the basis of how well they travel without getting damaged.

For health

The big one. The Food Standards Agency has been resolute in its refusal to endorse the view that organic food is ‘healthier’ than conventional alternatives; but there are studies which show that it may really be nutritionally superior. It is well documented that organic milk contains higher levels of essential fatty acids omega-3 and conjugated linoleic acid which are thought to play a part in healthy metabolism and brain function. Other studies have shown that even something as inconsequential as organic tomato ketchup contains more of the ‘cancer-fighting’ chemical lycopene than non-organic brands; and researchers at the Danish Institute of Agricultural Sciences (2002) concluded that rats fed on an exclusively organic diet had stronger immune systems and were less prone to obesity than their peers who were given conventionally-grown food. Using Medical Research Council data, David Thompson (2002) found that the mineral content of many dietary staples appeared to have declined dramatically since the Second World War (for example, carrots had lost 75% of their magnesium), and speculates that the widespread use of artificial fertilizers may be to blame for this. And while the health effects of chemicals sprayed on crops as pesticides is still unclear, the UK’s Pesticide Action Network describes many of them as known or likely carcinogens and endocrine disruptors. Whether any of this is actually significant or not is up to individuals to decide; but in the meantime, why take the risk?

For wildlife

The cornerstone of the organic approach is maintaining good soil health. A healthy soil, rich in organic matter will support a whole ecosystem and provide food for birds, amphibians and small mammals. Use of chemicals can interfere with this. Although modern pesticides and herbicides are rarely directly toxic to non-aquatic vertebrates, their use may still contribute to a fall in population numbers because they lead to a reduction in the number of seeds, insects and soil-dwelling organisms available for food; and they may have an indirect effect on populations through endocrine (fertility) disruption.

For the planet

Industrial food production is, not surprisingly, built on an industrial process: in 1909, a German physical chemist called Fritz Haber developed a high-temperature, high-pressure process to fix atmospheric nitrogen. At first this was only possible in lab conditions but before long, another Germanchemist,Carl Bosch, had worked out a way of adapting the process to a factory scale. The Haber-Bosch process was born.

We have many reasons to thank Mssrs Haber and Bosch. The process to which they gave their names transformed agriculture. By making available huge quantities of atmospheric nitrogen which could be returned to the land as fertilizer, Haber-Bosch has been the driving force behind the twentieth century’s massive rise in agricultural yields. Without it, it’s unlikely we could sustain world populations at their current level. But there are downsides. When the luxuriant growth promoted by nitrogen fertilizers occurs in the wrong place, the results can be catastrophic. Huge algal blooms which have reduced areas of the Gulf of Mexico to little more than ‘dead zones’ have been attributed to fertilizer ‘run off’ into rivers draining the American mid-west. Most notably, however, Haber-Bosch is not a sustainable technology.

Industrial nitrogen fixation is a high-energy, fuel-hungry process - and most of that fuel comes from non-renewable sources. It also depends on a natural gas ’feed’ to provide a source of hydrogen – this is integral to the chemical processes in nitrogen fixaton. Some authorities estimate that between 3 and 5% of the world’s annual natural gas production is used in fertilizer production. And while others might counter that sustaining a large chunk of the world’s population is a worthwhile use of energy, it is generally agreed that alternatives are needed.

Can organic agriculture replace Haber-Bosch, and still feed the world? Many would say not. But on your allotment, it can. There are enough alternatives for you not to need industrially-produced fertilizer for small-scale gardening.

For legal reasons

Since 2003, many pesticides have been banned by the EU. You are now obliged to rely on organic methods only to control a range of garden pests. So we are all organic now.

Partly organic?

Around allotment sites, you will sometimes hear gardeners claim that they are ‘partly organic’ or ‘organic in some things’, position statements which others find unintelligible or even downright illogical. But it does raise the interesting question of whether there are, in fact, shades of organicness in gardening. At one level, the answer is a definite 'no'. In Britain, the ‘rules’ of organic husbandry are laid down by the Soil Association, the main UK certifying body, and ‘interpreted’ for backyard and allotment gardeners by Garden Organic, the organic gardening charity. Ergo, if you don’t follow these rules, you are not gardening organically. The reasoning behind this view is easily understood: the organic garden should function as an integrated system, and if one part of this system is not in harmony with the rest, it is no longer a system at all. On the other hand, some of these rules have been characterized as arbitrary, and not adapted to individual circumstances. And for reasons of pragmatism or economy, many gardeners who do not advertise themselves as organic habitually reuse and recycle, make compost and rarely use pesticides. Is it really fair to write them off as ‘part of the problem’?