A survivor since the days of the dinosaur, field horsetail--also known as mare's tail--is a particularly nasty weed in many parts of Europe, Canada and the United States. Horsetail is commonly found in non-cultivated sites such as roadside ditches, meadows, sunny hillsides and sandy beaches.
Horsetail grows in many different habitats and defies destruction, a survivor in every type of soil.
Fertile horsetail stems appear in the early spring, and a single spore cone can release more than a million minute spores. It is easy to see why this pesky plant is difficult to eradicate.
In small areas, dig up the plant, making sure to eradicate all of the roots. If portions of the root remain, the horsetail will continue to survive.
Incredibly hardy, common horsetail, Equisetum arvense was the first plant seen recovering after the 1980 Mount St. Helens eruption. Horsetail is most often found in areas where the soil has little or no nutritional content, such as sandy beaches or gravel pits. Raising the nutritional content of your soil by adding generous quantities of composted organic materials will, over time, get rid of horsetail.
Improve large areas of the landscape with sheet mulching. First, cut back the offending weed and spray with a high nitrogen spray. Cover the area with layers of cardboard, then cover that layer with weed-free top soil and leaf mulch. This method with kill off the horsetail and enrich the soil. Apply more sheet mulch each season to eradicate any stubborn plants that persist.
Treat small areas of infestation by spraying. The leaves of horsetail are tough and waxy, making it hard for a weed-killer to penetrate. Before spraying, break or bruise the plant to allow the weed-killer react with the plant. Walk on them or beat them with a shovel to break the stems. On a dry day, spray to moisten the plant and the surrounding soil. Choose a day with no rain predicted for 24 to 48 hours.
Choose to spray with an eco-friendly herbicide. Glyphosate-based products are biodegradable and will not poison the soil. Household vinegar is also an effective spray. Repeated applications may be necessary, but be cautious not to acidify your soil.
Treat in the fall and again in the spring as new shoots emerge.
Avoid the use of toxic chemicals that will pollute the surrounding soil.