Horsetail (Equisetum) is a noxious, invasive perennial weed common in North America and Europe where it invades gardens to offer strong competition for desirable plants. Other names for the weed include mare's tail, horse pipes, snake grass and joint grass. Horsetail features an extensive root system that grows and spreads deep in the ground, making it all the more difficult to remove. The tenacious, prehistoric weed requires determination, resilience and a number of strategies to eradicate it from the lawn or garden.
Pull the plant from the ground if the infestation is small and only a few weed plants exist. These plants haven't had a chance to release spores and multiply, so eradicating them when they are fewer is easier than dealing with a large infestation. Grasp the main stem of the horsetail plant and pull it out of the slightly moist soil. Loosen the soil with a hand trowel to make it workable, so you pull out the entire plant along with the roots. Collect the dead plants and discard.
Mow the horsetail plants as short as possible in spring. Alternatively, cut the plants as short as possible using a hand-held cutting tool if the infestation is small or the weeds are scattered randomly. Inspect the plant for signs of regrowth and cut again. Continual cutting before the buds develop and grow prevents the spores from spreading, thus controlling spread. Repeated cutting also weakens the structure of the plant, causing it to die.
Spray the weed plant with a glyphosate herbicide. Depending on the label spray the herbicide directly over the plant or dilute it in the pump sprayer before application. You need 4 qt. for every acre of land. Douse each weed completely before moving to the next weed plant. Plants begin and weaken and die in five to seven days. Repeat application over stubborn plants, if necessary.
Cover the plants with a thick sheet of plastic that prevents sunlight, moisture and air from filtering through, killing it in up to three months. Extend the sheet over the edges to prevent access to these essential elements. Inspect the edges for stubborn sprouts and pull these out of the soil promptly.
Puncture the weed plant with a trowel or cut it as close to the ground as possible and douse it with a vinegar-based spray. The spray penetrates the inner tissue of the weed and burns it.
Horsetail is a tenacious plant that will require continual effort to completely eradicate from your area. If spraying glyphosate on the weed, select a day with no forecast of wind or rain 24 hours prior to and after application.