Country & garden: Herbs No 4: Comfrey

I WISH that I could have swapped my school botany teacher for Aristotle, a man observant enough to have discovered that the greenfinch in spring lays a blanket of comfrey (Symphytum officinale) on an under- nest of hair and wool. (For other interesting nature notes, read his The History of Animals.)

No plant has a wider range of names or more soundly established properties than comfrey. The name derives from confervere; con firma means to grow together, a tribute to the plant's reputation for healing broken bones.

Pliny recommended comfrey; medieval herbalists called it "bone-set" and kept jars of the root, lifted and grated in spring. "Bruisewort" and "knitbone" indicate the same use, while "church bells" is a pretty reference to the drooping clusters of purple and white flowers. So, less prettily, is "ass ear"; but what about "Abraham", "Isaac and Joseph", "pigweed" and "gooseberry pie"?

Gooseberries and comfrey don't sound a promising mix - but you can eat the stalks, blanched, like skinny asparagus. An upturned flowerpot will do the job of blanching in situ. Enthusiasts cook the young leaves like spinach. Comfrey wine is a waste of time and effort and I've yet to meet anybody who's made chutney from the roots, though it can be done. Comfrey coffee, if you must, is also made from the roots.

Curing, not cooking, is comfrey's main function and its almost legendary power is due to a chemical called allantoin, in the leaves. (Allantoin is the miracle ingredient in Clearasil's spot-blitzing face-cleanser.) As a tea, it's been used for everything from bronchitis to haemorrhaging. The wives of Crusaders sent them off to war with a tightly sealed jar packed with the leaves. These eventually turned into an oily brew that could be rubbed on wounds - and worked.

Even at the beginning of this century, Yorkshire miners used comfrey for the aptly named "beet knee", acquired from crawling along narrow seams. A poultice of hot comfrey leaves was guaranteed to bring the swelling down within 24 hours. Less plausibly, a hot poultice spread on to the scalp is alleged to encourage hair growth. Ask yourself first why, if this method works, it has not been marketed.

Manure is not a very romantic topic, but don't overlook comfrey when preparing some. A plastic carrier-bag stuffed with wet comfrey leaves is claimed to produce an uncommonly powerful nutrient for tomato plants. If you don't have any, follow a tip from The Wind in the Willows and get thee to "the pageant of the riverbank" to gather some. But, before adding comfrey's rose-pink or purple flowers to your garden border, remember that you will never be rid of it. Comfrey springs up from severed roots faster than soldiers from the field Jason dutifully scattered with dragons' teeth.

Anyone in doubt of comfrey's miraculous powers of healing might be converted by this story, which is told in Richard Mabey's Flora Brittanica. One of his correspondents, a doctor, wrote to tell him about a patient who had failed to respond to every kind of dressing for a wound on his leg. The wound only healed after the dressing was soaked in an infusion of comfrey plants. Convinced?