Guest post: A Canadian gardener visits Chelsea
Chelsea Flower Show Plant of The Year

Vexing nettles

White dead nettle, Lamium, in flower with the paler foliage of stinging nettle, Urtica. Image ©

There are nettles, and there are nettles.

The perennial stinging nettle, Urtica dioica, is often the first British wild plant that kids learn to recognise - because they get stung. The leaves are covered in stinging hairs which contain formic acid, histamine and seratonin. Its annual relation, Urtica urens, actually has a denser concentration of stinging hairs, but the plants are much smaller so the damage to a tumbling child is usually much less.

In the US, two native American subspecies are found as well as the European form which is naturalised over most of the country.

The stings are not dangerous, although a related species in New Zealand is rumoured to have killed horses! But they are not pleasant and come with a red rash – especailly after you’ve scratched it. The cure often grows conveniently alongside – rubbing the stung area with dock leaves, broad-leaved dock, Rumex obtusifolius, for example, takes the edge off the pain.

But also often growing with stinging nettles is white dead nettle, Lamium album (above, click to enlarge) – “dead”, with no sting. When not in flower, stinging nettle and dead nettle look alike with the similarly shaped and sized leaves gathered in pairs along upright stems.

The dead nettle stems tend to be fatter and more obviously square, but when the two-lipped white flowers open the distinction is obvious; nettle flowers come in relatively unobtrusive green tassels. Kids tend not trust the distinction.

Stinging nettles are actually very useful plants; paper can be made from the stems; the foliage is important as food and shelter for many caterpillars; the young shoots can be eaten steamed or made into soup. Nettles have also been used to treat a wide variety of maladies.

And keeping nettles in your pocket is said to protect you from being struck by lightning. Of course, if you misidentified the plant and keep dead nettle in your pocket by mistake – when the lightning strikes, dead is exactly what you’ll be.