Stinging Nettle (Urtica dioica L.)

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The stinging nettle is one of my favorite plants. It might sound strange to care so much for a plant that, upon touching it, injects you with a fluid containing histamine and other substances that cause a painful burning sensation and a numbness that could last for hours. Yet, the humble nettle is so versatile that it grows on you (but not literally, please). And what's more, once you become acquainted with it, you learn to grab the leaves in a way that crushes the stinging hairs before getting burned, a knowledge that unfortunately will not be of much use if you happen to fall (or be dragged by your dog) onto a large patch of nettles...

Even though I haven't read Victor Hugo's novel Les Misérables, when researching for this post I came across this great quote: "When the nettle is young, its leaf forms an excellent vegetable; when it matures, it has filaments and fibres like hemp and flax. Nettle fabric is as good as canvas. Chopped, the nettle is good for poultry; pounded it is good for cattle. The seed of the nettle mingled with fodder imparts a gloss to the coats of animals; its root mixed with salt produces a beautiful yellow colour. It is besides excellent hay and can be cut twice. And what does the nettle require? Little earth, no attention, no cultivation."

Nettles emerging above last years' dry leaves.

To the last sentence I can attest: nettle grows in my garden without any effort on my part, and it's also very abundant in the forests and fields nearby. This perennial plant that can be found worldwide, and while there are a number of Urtica species, and even a few different subspecies of U. dioica (including some without stinging hairs), most literature refers simply to U. dioica, also known as the "common" stinging nettle, native to Europe and Asia. The name urtica derives from the Latin word uro (to burn), while dioica comes from the Greek and means "two houses", which reflects that the plant grows male and female flowers in separate plants. Nettle can grow quite tall, sometimes reaching a height of more than 1 meter. Its stem is square and its serrated leaves are easy to recognize. Between June and September, long clusters of green flowers appear. While it is possible to distinguish the male and the female flowers, in practice I find it's not so easy, so I'll spare myself having to explain it by linking to this article. Nettles spread through underground rhizomes and runners, so they can easily cover large, dense patches. 

Here it is easier to distinguish the stinging hairs.

Looking at this simple weed, you probably wouldn't guess how rich in vitamins and minerals it is. Nettle leaves are a very good source of vitamins A and C, iron, and calcium, among others. Its constituents also include flavonoids, tannins and caffeic acid derivatives, which also contribute to its medicinal properties. 

To use nettle in the kitchen, you only need to blanch the leaves in hot water for a very short time to remove the sting, and then you can use them as you would use spinach. In Germany, nettle is often used in Gründonnerstagsuppe (Green Thursday soup—which refers to Holy Thursday in the Easter season). This soup is traditionally prepared in spring with the first herbs that emerge to energize the body after the long, cold, dark winter. Some recipes call for seven herbs, others for nine, and the specific herbs can vary according to taste and availability, but nettle is almost always present.

As for the medicinal uses, nettle leaves and their preparations are used internally and externally to treat a myriad of conditions, including rheumatic diseases, kidney and urinary tract problems, hay fever symptoms, and skin problems such as eczema and psoriasis. Since the ancient Romans' time (and maybe even earlier), people would flog themselves with stinging nettles to warm the body and relieve pain, a therapy called "urtication", which some brave individuals still use. Following the idea of the Green Thursday Soup, nettle can also be part of a "spring cleansing" of the body, in preparations used as spring tonics, or simply as a tea to be drunk a few times a day. An alcohol-based tincture of the leaves can be applied to the scalp to promote hair growth, and nettle is also in many commercially available shampoos and hair care products to control dandruff and reduce scalp oiliness. The root has been found to help in the treatment of problems associated with prostate enlargement. 

In Autumn one can also collect nettle seeds. Once the flowering period has passed, I cut the threads, dry them in the oven at low temperature, and then rub them carefully to separate the seeds. While this process can be a bit laborious, the seeds have a great "nutty" taste (I like to sprinkle them on top of bread with jam), and are sometimes even called a "superfood". 

Following Victor Hugo's quote, I'll also mention that nettle fibers can be used to make clothing. While the making of nettle fabrics has lost importance and is now perhaps a bit niche, it is worth mentioning that Germany and Austria used nettles to make army uniforms due to a shortage of cotton during the First World War.

I'm sure it's possible to go on for many pages listing the many uses of this wonderful plant, but since I have to stop at some point, I'll finish by mentioning that it is also great for organic gardening. Nettle tea, a stinky but very effective preparation made by letting the leaves ferment in water for a few weeks is great as a fertilizer and helps to combat many pests. I'll conclude with a weird fact: in France, nettle tea for agricultural use has been the subject of a decades-long discussion. Selling and advertising it—and even telling others how to prepare it—were prohibited for years, on the grounds that it is a preparation similar to a fertilizer or pesticide. If you have the time, the knowledge of the French language, and the appetite to delve into the deepest absurdities of bureaucracy, be my guest and read a summary of the issue here.