COUNTRY & GARDEN: Herbs No 3: St John's Wort

SHORT ON the nicknames which the English have always loved to confer on herbs, St John's wort, Hypericum perforatum, is unusually strong in the magic department. Hypericum, in ancient Greek, meant "power over an apparition". A sprig of it placed under your pillow will give you the protection of John the Baptist against evil spirits. To make sure of keeping them away, flourish the sprig while saying: "Trefoil, vervain, St John's wort, dill, hinder witches of their will."

Any herb gathered on midsummer day is supposed, to have special powers. None among them is more powerful than St John's wort, this being the day on which great bonfires in honour of St John used to be kindled in parts of Germany and Austria. Engaged couples jumped over the fire to establish by the height of their leap how long their days of married bliss would last.

In Brittany, any girl prepared to dance around nine of these fires could be sure of finding a husband before the year was out. A childless woman could make herself fertile by walking naked through her vegetable garden on St John's Eve.

A French proverb tells of using "all the herbs of St John" to bring about a love- affair. The user was expected to fast for a day and then go out before sunrise on St John's Day to pick the flowers which, if these conditions were met, would never wither.

Nobody could object to the golden flowers of hypericum, but it is not the plant's looks that have made it one of the world's most popular herbs. Even in the days of Hippocrates, St John's wort was recognised as an impressive healer of wounds; in the past few years, it has become celebrated as one of the best antidotes for depression since Prozac. Writing as somebody used to waking up in a state of inconsolable melancholy, I can promise you it works, so long as you give it a month for the effects to begin. I've heard reports that it is also effective as a sedative, and even as a cure for hangovers.

Don't however, try eating the plant itself: all you'll get is tummyache and red fingers from the stems and the black dots on the petals. These, according to the legend, are where St John dropped his blood. Perforatum refers to these minute "perforations", in fact resin glands giving off the sharp smell that reputedly kept witches at bay.

I've had no luck in tracking down the receipt for the mysterious Ointment of Elemi, involving St John's wort and turpentine, which was invented by a 16th-century Spanish doctor working in Amsterdam. As a consolation, here is an easily prepared soother of scalds, sunburn and grazes: pack a glass jar with the flowers. Pour oil over them (walnut or sunflower is best), seal and stand it in a sunny position for two weeks. Drain through a jelly bag into a jar or bottle of dark glass and store in a cool place. Capsules are available from chemists. It's not for nothing that they're often referred to as "joy pills".