Alert List for Environmental Weeds
Department of the Environment and Heritage and the CRC for Australian Weed Management, 2003
ISBN 1 9209 3224 0
About the guide
Horsetails (Equisetum spp.) are on the Alert List for Environmental Weeds, a list of 28 non-native plants that threaten biodiversity and cause other environmental damage. Although only in the early stages of establishment, these weeds have the potential to seriously degrade Australia's ecosystems.
The popularity of interesting foliage plants for landscaping in Australian gardens is contributing to a local increase in horsetails, which are among the world's worst weeds. Several species are being sold for use in Australian gardens. Horsetails are also promoted for medicinal purposes.
As well as being highly invasive, horsetails are toxic to livestock and can even kill animals that eat contaminated hay. Horses, cattle and sheep are particularly susceptible and can die within a few hours of eating large amounts of the plants. In high densities, horsetails reduce crop yields by producing inhibitory substances that depress the growth of neighbouring plants.