Herb to Know: Horsetail


Content Tools

Genus: Equisetum arvense

• Zones 2 to 9

Prehistoric and somewhat bizarre, this rush-like plant cleans up in more ways than one.

If asparagus and running bamboo were ever to collide, they might produce an offspring like horsetail. Slender, bright green hollow stems growing up to 2 feet high are segmented with striking bands of black and gray topped by a brownish, cone-shaped finial containing spores. Once the spores are released, the fertile stem is replaced by a non-fertile stem that looks more like a static firework display of streaming green threads.

Believed to be one of the oldest plants still in existence, medicinal use of horsetail dates back to at least the ancient Romans and Greeks, who reportedly used the plant to treat ulcers and wounds. In Colonial times, horsetail tea was used as a diuretic. Most likely, housewives also used the plant to clean the teapot, as it contains high concentrations of silicon, a natural abrasive.

Some say that silicon also contributes to healthy bones, cartilage and connective tissue. Many herb-alists recommend its use — only in consultation with a holistic practitioner — to help mend bone fractures, sprains, burns and wounds. Gardeners, on the other hand, prefer to brew up a pot of horsetail tea and spray it on susceptible garden plants to treat or prevent fungal diseases, such as mildew and rust.

Horsetail grows in moist woods, near ponds, streams and swamps as well as in fields and meadows, but it also can establish itself in places that are dry and barren, such as a roadway. The plant propagates by spores and spreads by creeping rhizomes, so it’s easy to establish — in fact, too easy. But if you’re keen to enjoy its bizarre beauty, you easily can keep it under control by growing it in planters or in buckets near a pond’s edge.

Reading List

The Green Pharmacy by James A. Duke (Rodale, 2000)
The Ultimate Book of Herbs & Herb Gardening by Jessica Houdret (Hermes House, 2002)
Herbal Renaissance by Steven Foster (Gibbs Smith, 1993)
Rodale’s Illustrated Encyclopedia of Herbs (Rodale Press, 1987)
PDR for Herbal Medicine, First Edition (Medical Economics Company, 1998)