Even if our urban children are beginning to think potatoes come from cows, surely the grown ups know that beans grow. People do still eat beans. True, shop beans are an easier gathering, but for the extra effort your own produce is priceless. I wonder if people imagine gardening is just for crooked old gardeners. Well, regardless of its reputation, for this city-dweller a bit of compact agriculture's is where it's at. For £20 a year, a bargain almost too unreal to believe, I've a plot of muck 60ft long. Often I wonder why people with gardens don't raise the odd row of vegetables. It's priceless.

It's not just a matter money that I home-grow, and not only that I love getting dirty. It's also that I hate supermarkets. Sure, I get my corned beef and my toothpaste there, I'm not a purist, but, for one thing, I shudder at aisle after aisle of plastic. Too much wasteful wrapping. On top of that, lots of the mass transported fruit and veg, sped over very long distances, has to be preserved. Haste is definitely a dinner-time requirement, but haste alone doesn't make your greens stay green and pretty. My rocket goes limp within seconds because it is not in a bag puffed with chlorine. I stick it in water when I get home and it's erect in seconds.

I sow my own seeds because - to keep up with living it large - on the one hand our culture is at pains to cut corners (stretching time and money even further), and on the other it demands extra output from us to do so. We collectively work harder to buy harder collectively. The market has a momentum of its own, and at work there appears to be a backlog we're always rushing to meet. So many people I meet have too much to do. I know some who now do the job of two people for the same pay as one.

Re-enter London after a trip away and its like landing on a spinning ball, a blink-and-you'll-miss-it kind of frenzy. You can almost feel the whiplash as you step off the train. This city's kept ticking along by one thing alone, the incredible - incredible - ability of its citizens to graft long hours, intensely, day in, day out. What is keeping us going? Gossip, beer, sport, new shoes, doughnuts, a raging love affair, someone's breasts, a belly laugh. Quick fix all round, whatever gets you through the day is worth its weight in gold, is it not? This is where convenience food comes in - making amends for feeling so knackered. It's kind of irresistible, and compared to pasta, broccoli fairs poorly at the till, too. From a gardener's view, though, nothing compares in any way to your own produce.

To rage against the machine and indulge your taste-buds on rebel chow, the first thing you need is a spade. The second is a good back, or a mate. The third is good horse-shit. I buy rotted stable manure in big bags for £3. I also purchase blood and guts, though I think its right name is blood, fish and bone meal. Plants take nutrients out of the soil, so as well as putting all that back in, the added roughage and gore is great for increasing drainage. Drainage is very important. Soil too wet is as disastrous as soil too dry for any prolonged period. There are all sorts of ways to help prepare and nourish your corner of earth fit to sow, and I make my own compost too. I grow prolific plant-matter that I cut down time and again and simply throw into a bin. Compost can be a fine art. If I lived nearer, I'd use my food waste - but I tried it once and it stank so much on re-opening I almost fainted. So, step one is soil enhancement (do the opposite to cosmetic surgery and you're away).

Next, you need good seeds. Try whatever you like. Be adventurous and learn what likes your soil and what doesn't. Then you can then either specialise in certain types of plant or change what you do to the earth. You may be surprised at the results. I practice a vague crop rotation. Some plants like recently-composted soil, others grow better if the old manure was dug in the year before. Things with edible leaves (cabbages, lettuce, spinach) like the richest soil, but roots (carrots, parsnips) fair better in less rich ground. It's not absolutely essential, but crop rotation accounts for all of this and also for the fact that plants can pick up disease and soil parasites from the previous year. So I rotate crops in three sections in two-to-three year cycles.

Gardening's a shock a minute. When something's in a good mood it'll grow as if you'd given it magic drugs. If it's miserable, it can droop and leave you overnight. Some plants and some strains within plants are utterly forgiving. You can't go much wrong with runner beans, for example. An attack of spider-mite - a beast which rampages all of London - will bring it to its knees, but will not stop it pushing out beans in its sorry state. Of course you don't want anything to be in a sorry state, which is why you watch and learn. Once you have the basics you only fine-tune to get healthier specimens. Start with something like Nero di Toscana Precoce, a rampant kale which, from a handful of plants, will green your plate almost all year round. In fact, kale, runner beans and lettuce are a sure introduction to any soil.

We all use seeds that have been bred and bred to increase edible output. This comes at a cost of a plant's natural defensiveness. Wild plants are not tasty, cultivated ones are. Aphids, snails and pigeons - they want my cabbages, not chickweed. As a result I have to net almost everything. If I spray it's a biodegradable concoction and used conservatively. If not, I squash parasites with my fingers, or eat them too, on whatever it is they have stuck themselves. My mate from Tulse Hill who keeps trying to give up smoking told me that if you dissolve a whole packet of Drum tobacco in some meths, then use the liquid diluted in water, you can annihilate all your black-fly in one catastrophic vapour and aid your de-addiction. It's cheaper than Nursery cocktails, if you're the experimental kind, but beware of home-made potions, as they may have the odd, unwanted side effect and are, in effect, poisoning something.

The most important thing you must know as a gardener is that the soil is alive. Soil is not the same all the way through, the topmost inch is especially active. It's best not to fiddle too much with your muck. If you dig it you need turn it over once a year, and it's best advised not to hoe all the time nor walk all over it. My friends don't understand why I say stick to the paths, it's just soil after all. What your feet are doing, though, is pressing out the air - and soil and roots need aeration, so does water absorption. An easy way to keep weeds down and protect exposed soil from sun and rain erosion is to lay bits of carpet down here and there. Hey presto, another living room, just don't walk on it! At night, when the sun is sinking, is the best time to water. As a party trick, my mother used to break an apple in half with her bare hands and I thank our family strength when I must to and fro to the water pump for fifteen runs of filling watering cans.

I enjoy watching a garden grow. It grows fast. Life itself always tries to get more gain for less expenditure. That's why your plants are the bulls-eye for so many critters, because they have a rich yield for a small area - it's paradise. But there's one thing that I've learned from working directly with earth and food, and that is that you can't actually get profit without loss - somewhere in the chain. Which means, taking the bigger picture, there is no overall profit. It's dog eats dog and if you want to know about systems and economics, start growing carrots.

We're facing the fact that there's a certain amount of energy about and you can't make more. All you can do is redistribute capital and try to manage the resource that's under your feet or over your head. Remember, you are trying to harness one thing, the goodness from photons, from rain minerals and decay, which plants combine by looking up and reaching down. And you're trying to make this combination bring about succulent edible matter for you to live off, or at least, enjoy.

Why grow food when you can buy it? Surely the idea of packing in yet another activity is too much? No, I'm glad I stuck it out. After reaping the rewards I now see growing my own food as essential. I have a bench and after a while I get to spread my arms along the back of it and do nothing at all because I am in allotment-job credit. I love this place. It does me the world of good. Like the smells of the bedroom are to your human desires so the vapours at dusk are to a lust for life. There is nothing too trivial about our great garden. At sundown the bugs and beasts get active and the place bursts into another sort of life. It's funny speaking of carpet earlier because I heard some time back that the best way to get rid of the clouds of whitefly on your cabbages is to Hoover them. I'm very glad to say there is, however, no electricity down here. Here, when the light goes out, the light goes out, and I cherish that. I will just have to live with the whitefly. I will eat their cities along with their leaves.

END

(c) Alison Trower 24 March 2009

Alison Trower is a writer and director living in London

Fringe Report (c) Fringe Report 2002-2012

www.fringereport.com