Horsetail is a noxious weed that has survived millions of year to become one of the most tenacious weeds today. It is toxic for horses, sheep and cattle when consumed. Horsetail is difficult to eradicate despite a home gardeners best efforts. It spreads by spores carried by the wind every spring and by its tubers. It thrives in wet soils, which is why it is commonly found near rivers, lakes roadsides and ponds. This perennial weed has a deep and extensive root system and survives the cold winter.
Wear your gloves and dig up a small horsetail plant with a shovel, making sure to get all the roots. Even the smallest piece of rootstock will grow into a horsetail plant. Promptly collect it in a plastic bag, knot it securely and dispose of appropriately.
Chop or mow horsetail weed to ground level if the plant is large or covers a vast area. Put the foliage in a plastic bag and dispose of appropriately.
Break the thick stem or slash it with a sharp knife or shovel in several places. Make sure the gashes are deep enough and bruise the plant. Douse the plant in commercial weed killer that contains glyphosate, pouring directly over and around it. The weed killer will penetrate the gashes and eventually kill the horsetail plant. Treat any new growth promptly, and reapply the herbicide later in the season, or early next season to eradicate it permanently.
Pour vinegar directly over the horsetail plant and the soil around it on a dry day to eradicate it from your lawn. Horticulture vinegar is stronger than household vinegar and kills young plants immediately. Reapplication may be required the next day and for a few days after, however, for mature plants .
Smother the horsetail plants as an alternative to applying weed killer to it. Spread a plastic sheet or a 1/2-inch thick cardboard over the mowed plant and poke holes in it to allow mulch to penetrate. Spread a thick layer, at least 5 to 6 inches, of pine bark or mulch over the sheet; leave it for four to five months. The plants will compress under the weight and eventually die due to lack of oxygen.