How does one eradicate horsetail/equisetum? When it was planted, it seemed like a good idea, but now it is taking over desirable plants. Can equisetum be controlled by planting in a container? How does it spread, by rhizomes or spores?

Gardens & Landscapes August 31, 2011|Print

Biology and Control of Field Horsetail   Excerpt - "Presence and Control in Non-cropland - Horsetail is becoming more common in non-cultivated sites such as roadsides, flower beds, lawns, ornamental plantings and sandy beaches. Even if repeated tillage could be done, it may not be successful. Horseweed’s extensive and deep rhizome system means that tillage and cultivation only destroy the top growth and delay reestablishment. The density of many perennial weeds can be greatly reduced with a season of repeated tillage. However, weed scientists in Canada hand-weeded an area with horsetail 16 times during one summer. The following year these plots looked identical to the check plot (Cloutier and Watson, 1985)! Even glyphosate fails to control horsetail. A home owner reported using glyphosate three times in one season to kill horsetail: the next year the site sported a dense monoculture of horsetail. The Weed Control Manual 2000 (Curran, et al., 2000) lists only two herbicides for field horsetail control in non-cropland, ornamentals/woody plantings, small fruits, and deciduous tree fruits: diclobenil (Casoron) for all the above sites/crops; and clorsulfuron (Telar) or sulfometuron (Oust) for non-crop areas. No references on the long-term effects of these herbicides on horsetail were found. Follow label guidelines carefully if either of these herbicides is used." A homeowner would probably have to contract with a firm that has a commercial pesticide applicator's license to purchase and apply these chemicals. Spread — mostly by rhizomes but it can spread by spores. Even set in a pot these plants can move out through the drain hole if it is not permanently blocked or over the edge of the pot. And then of course there are the spores.   http://fyi.uwex.edu/weedsci/2001/05/02/biology-and-control-of-field-horsetail/