Nettles

Image: Jerome Prohaska

Near the abandoned watercress beds, within a few yards of the stream, the ruins of an old cottage adjoin the footpath. The rubble is overgrown with stinging nettles, which protect the precincts of the cottage from intrusion.

By the middle of July the nettles have reached their greatest height. They grow here so well because the soil is rich in nitrogen – bequeathed by the middens and latrines of the former occupants. The plants are getting old and tough now, and even more uncompromising than they were in the spring. A bed of “stingers” is agony to walk through with bare legs and arms, and usually receives a punitory slashing from the countryman’s stick.

Is this punishment deserved? The nettle, after all, is only protecting its own, and uses the same irritant, formic acid, that is found in ants’ stings. Both weapons have the same purpose – to repel invaders.

The nettle’s stinging organ is simple but effective, a modified hair, long and hollow and with a swollen base into which the acid is secreted. The point of the sting is formed by a very sharp, very thin scale of silica (the basic ingredient of sand or glass). The scale is so sharp that even the slightest contact causes it to break off in the skin, making a tiny wound, and the acid is then squirted into the wound by contraction of the base, rather as in a hypodermic syringe.

If the plant is wilting, dried, or cooked, the mechanism will not work; and if you “grasp the nettle” you will not be so much stung, for many of the hairs will be bent or crushed before they have a chance to act.

The sting was probably evolved as protection from the browsing lips and tongues of deer and wild cattle, for the nettle was originally a plant of lightly shaded woodland and clearings. It is dioecious (having “two houses”), which means that the straggly catkins of male and female flowers are found on separate plants. The male flower has four stamens, each bearing a pollen-laden anther at its tip. The stamens are sharply bent inwards to the centre of the flower, being released like catapults to send their pollen dust drifting on the wind.

The flowers are rather reminiscent of those of the cannabis plant, and inside a big nettle bed, especially after a long spell of dry weather, the smell is distinctly redolent of the forbidden weed – which is not to be wondered at, because the two plants belong to closely related families.

Like cannabis, which provides the hemp fibres used still in making rope, the nettle also yields fibres which can be woven; at one time in Europe, especially in Scandinavia, nettles were widely used for this purpose. Fragments of nettle cloth have been found in a Bronze Age grave in Denmark, and cloth was produced commercially in Silesia as late as 1920. Indeed the Germans, during World War I, turned to the nettle when their cotton supply was cut off, and used it for making military clothing. Over two thousand tons of fresh plants were taken from the wild, although it needed nearly ninety pounds to make just one shirt!

Nettle makes an unexpectedly good fabric, strong and light and fine, and a nineteenth century Scottish poet, Thomas Campbell, writes of sleeping in nettle sheets and dining from a nettle tablecloth. The stalks are picked in late summer, dried, stacked, and then wetted so that they begin to rot. Next they are dried again, and beaten to remove the rotten tissue from the fibres. The fibres can then be spun into thread, like flax or cotton (though nettle fibres are not so long), and woven in the ordinary way.

The commercial growing of nettles in England in medieval times is perhaps echoed in such place-names as Nettlebed (near Henley-on-Thames) or Nettleden, near Hemel Hempstead.

Besides the cloth, nettles will make the dye, provided it is fixed with the right mordant, alum. Admittedly the colour is rather a dull green, but it was this very quality that led to our use of nettles in the Second World War. We used hundreds of tons of them for dyeing camouflage nets.

They also provided a ready source of chlorophyll. The nettle is rich besides in calcium, potassium, iron, sulphur, and vitamins A and C. The young shoots, which do not sting, can be eaten in spring as a salad or cooked like spinach and served with butter and pepper. When dried, they make a herbal tea. A year or two ago I experimented with some wild herbal teas, and although most were pretty disgusting, the nettle tea I could at least drink more than once. It had a delicate aroma and was curiously warming, like a glass of brandy. When added in small quantity to an Oriental tea, the nettle imparts a most unusual and exotic flavour which is well worth sampling.

Nettles figure in a number of herbal beauty formulae. An infusion of young or dried leaves is supposed to make a very good skin toner and an astrigent bath additive.

It is as a medicinal herb, though, that the nettle really comes into its own, and has been used, with greater or lesser success, in recipes to treat a wide range of maladies, including bronchitis, whooping cough, pleurisy, and other chest complaints; diabetes, dropsy, gout, rheumatism, varicose veins, menstrual problems, diarrhoea, constipation (yes, both!), stomach ulcers, and piles.

Some of these cures are undoubtedly effective in some cases, and the nettle was a highly prized addition to the pharmacopoeia in former times.

In return for all this bounty, our ancestors were able to forgive the nettle its sting. Next time we pass this ruined cottage by the stream and feel like wielding the big stick, perhaps we should do the same.

(Introduction to these pieces; see all)