For years, a friend of mine called my clump of horsetail “asparagus”. When she spoke of it, we were always sitting in rockers on the curving herb porch, looking out over the culinary and medicinal herb beds. She would point and say, “Jim, your asparagus always looks perfect. What do you do?”
Finally, one day, as we walked along the path between the culinary and medicinal beds, she stopped beside the horsetail and said, “I think your asparagus is fake. It always looks the same regardless of the time of year I visit.” From the herb porch, in a straight line with the asparagus bed but much nearer, is my stand of horsetail. All those years when she complimented my asparagus, she was seeing horsetail.
Horsetail (Equisetum hyemale), also known as shavegrass or scouring rush, is an ancient herb. Herb references say that this plant hasn’t changed in eons and probably looked in the time of dinosaurs just as it does today.
I had noticed for years that horsetail was listed as a folk treatment for kidney disorders; however, in Field Guide to Medicinal Plants: Eastern and Central North America (Boston: Houghton Mifflin, 1990), Steven Foster and James A. Duke list it as toxic to livestock and questionable for humans because it disturbs thiamine metabolism. Not a good recommendation for using an old folk remedy today!
But I had also noted in several sources that horsetail is useful as a natural fungicide. I’ve used it successfully as a treatment for black spot and powdery mildew on roses and noticed this year that a few organic supply companies are offering horsetail for that purpose. I add 1 cup of chopped horsetail to 6 cups of boiling water, boil for 5 minutes, then allow the tea to cool overnight. I strain it well and put it in a spray bottle. In damp weather, I spray the roses about every three days.
I surmised that if horsetail is a good plant fungicide, it might also be useful on skin. I first tested it on myself to see what effect it would have on athlete’s foot. I’ve used almost every product on the market only to have the athlete’s foot fungus go away for a while and then return, more bothersome than before.
To make the athlete’s foot soak, I mixed 1 cup of chopped horsetail plant with 4 cups of boiling cider vinegar. I boiled it briefly, then let it steep overnight. I strained the solution into a plastic shoebox. Every morning after showering, I soaked my feet briefly. Within ten days, the tenacious fungus subsided, and it has stayed away permanently.
I next tested horsetail on my father, who is close to being antiherbal: if it grows in the garden and isn’t a vegetable, he’s not interested. A few years back, he showed me his fingernails. One was totally black, and another was about half blackened. “I don’t suppose you have anything herbal for this?” Dad asked. “The doctor says it’s a fingernail fungus and that he’ll eventually have to remove the nails.”
Since then, I’ve learned that this fungus is common, especially in the fingernails and toenails of older people. While there is a medical treatment, it is expensive and often unsuccessful.
I mixed up my horsetail-in-vinegar solution for Dad and put some in a small glass. I encouraged him to soak his fingers for five minutes every night while he watched the evening news.
About ten days later, he called me. “The doctor wants to talk to you,” he said. “He wants to know what you’ve been using on my fingers because the nails are beginning to grow back.”
The nails healed completely, and the fungus has not returned.
Horsetail is, in addition, an interesting landscape plant and well worth including in the garden, but it is quickly invasive. It will grow under walks and out of beds. I grow mine in a five-gallon nursery pot with the bottom cut out. I fill the pot with soil and bury it up to the rim with the plant inside. The depth of the pot keeps the roots from straying.
The plant is said to prefer sandy, moist soil, but I’ve also found it growing in dry, gravelly railroad beds, along highways, and in heavy clay. It will grow in almost any hardiness zone.
Horsetail is a good example of an old folk remedy that doesn’t work for the purposes it’s remembered for yet has some beneficial uses today. It has a place of honor in my medicinal beds. From a distance, on a lazy afternoon, it may resemble stalks of asparagus, ready to be picked.
Jim Long is an herbalist and the owner of Long Creek Herb Farm in Oak Grove, Arkansas.