0f all the idiocies that supermarkets foist upon us, plastic bags of salad win the prize. Who is so inept as to be incapable of washing whole lettuces? Why do people waste their money on shreds of super-expensive greenery with fancy names? I agree that those round, viridian Dutch lettuces taste only of cotton wool. But must the alternative really be beet tops and turnip tops, Japanese this and that, all flown in from the other side of the world at enormous expense? Those lucky enough to have gardens, or canny and determined enough to have allotments, can feel sorry for the fashion victims who don't know what proper food tastes like. But even if we buy our salads rather than grow them, we could still demand an end to those ridiculous and overpriced designer ensembles.

There is an argument for convenience food. For hardworking women it saves time, and it is still women who mostly put the food on the table. I remember how, back in the glorious 1970s, we earnestly debated the labour theory of value as it applied to shopping, cooking and housework. Convenience foods were allowed to be a Good Thing, even a slap in the face to the bourgeois magazines trying to keep us pregnant and barefoot in the kitchen. But nobody then dreamt that people would stop cooking altogether and rely on microwaving chilled ready-meals instead.

My father grew lettuces in his vegetable patch in the back garden. They had roots. With earth on. You washed them, picking out the slugs and caterpillars, and then put them in the old wire egg-basket, which you swung energetically back and forth outside the back door, aiming the spray at your younger brother. Now, years after my father's death, I too grow vegetables. Digging and planting, I remember Dad, and feel close to him. I hear his voice explaining how to start the broad beans early, how to set the leeks. How beautiful he looked, leaning on his spade, in his shabby old trousers and shirt and wellingtons.

In the summer in France, everybody has gluts of lettuces. We put them in to cook with the peas, and I make soup, too. Yvette, who can't bear to waste anything, gives me her towers of bolted lettuces so that I can have my favourite soup every night. Frisees are our other summer treat, delicious tossed with new potatoes and olive oil.

All these delights are mistrusted by the profit-hungry supermarkets, which persuade us to swallow insipid rubbish. Heathcote Williams, when I was poetry editor for City Limits magazine, once sent me a terrific poem. His fine polemic asserted that the people who ran supermarkets must be Buddhists; there was nothing in them you could possibly want. Lettuce rejoice!