Urtica procera

Muhl.

Stinging nettle

Urticaceae Edible: Leaves Potential hazards — see below 2,946 iNaturalist observations

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Summary

A perennial nettle growing 1.5 m tall, fully frost-hardy. Dioecious flowering June to August, requiring both sexes for seed production via wind pollination; not self-fertile. Thrives in light sandy, medium loamy, and heavy clay soils with mildly acidic to basic pH. Establishes in semi-shade or open sun with preference for moist soil.

Description

Edible Uses

Young leaves are cooked and eaten — a highly nutritious food, rich in vitamins and minerals, that makes an excellent spinach substitute and can be added to soups and stews. Only young leaves should be harvested, and stout gloves are needed to avoid being stung. Although fresh leaves carry stinging hairs, these are fully destroyed by thorough drying or cooking. The young shoots are used to brew nettle beer.

Medicinal Uses

The leaves are haemostatic, antidandruff, and antirheumatic. Dried and ground to a powder, the leaves can be used as a snuff to treat nosebleeds. For rheumatism, fresh leaves are rubbed or beaten onto the skin — a practice called urtification — causing intense irritation. This is thought to work as a counter-irritant, drawing blood to the area to help clear rheumatic toxins, while the formic acid in the stings is believed to benefit the affected joints. A shampoo made from the leaves is used to treat dandruff.

Known Hazards

As every other species of Urtica, it has stinging hairs that irritate the skin. This is prevented by cooking it and using the young leaves instead, because older leaves develop cystoliths which act as an irritant to the kidneys.

Distribution

It is a temperate plant.

Where It Grows

North America, USA,

Cultivation

We have very little information on this species and do not know if it will be hardy in Britain, though judging by its native range it should succeed outdoors in most parts of the country. The Flora of North America treats this taxon as no more than a synonym for U. gracilis and also treats that taxon as a sub-species of U. dioica. The following notes are based on the general needs of the genus. Prefers a nitrogen-rich soil. The best fibre is produced when plants are grown on deep fertile soils. Dioecious. Male and female plants must be grown if seed is required.

Propagation

Sow seed in spring in a cold frame, barely covering it. Prick seedlings into individual pots once large enough to handle, then plant out in summer. Division can be done at almost any point during the growing season — straightforward enough to plant directly into permanent positions.

Other Uses

The stems yield a strong flax-like fibre used for string, cloth, and good-quality paper. It is harvested as the plant begins to die back in early autumn and retted before the fibres are extracted. A hair wash made from an infusion of the leaves is used as a tonic and antidandruff treatment. The leftover plant matter after fibre extraction is a useful biomass source and has been used in manufacturing sugar, starch, protein, and ethyl alcohol. Oil from the seeds serves as an illuminant. The plant is an essential ingredient in 'QR' herbal compost activator — a dried, powdered herbal blend that speeds up bacterial activity in compost heaps. The leaves are also a fine compost addition and can be soaked in water for 7–21 days to produce a nutritious liquid plant feed that doubles as an insect repellent and foliar feed. The growing plant raises the essential oil content of nearby plants, boosting their resistance to insect pests. Freshly cut stems repel flies and have been kept in food cupboards for this purpose. The plant's juice, or a decoction made by boiling it in a strong salt solution, curdles milk and works as a rennet substitute; the same juice rubbed into leaky wooden tubs coagulates and makes them watertight. A permanent green dye comes from a decoction of the leaves and stems; a yellow dye is obtained from the root boiled with alum.