A common feature of all these weeds is their ability to spread rapidly and form a dense mat above or below the water. This mat stops light entering the water and depletes the water body of oxygen. Fish and other creatures will die and all the native plants will be shaded out. Horsetails have deep, invasive rhizomes and ahve become serious weds in other parts of the world. They grow in damp soil and are a threat to wetlands, water courses, irrigated pastures and horticulture.
Horsetails are also toxic to livestock.
All Equisetum spp. must be destroyed. If you see any of these water plants, or others appear to be spreading rapidly, note their location and notify the nearest office of Agriculture Western Australia. Aquarium and pond owners Do not dispose of any plant from your aquarium or pond in or near any waterway or drain. Apart from horsetail, all of these plants can be killed by being dried out on newspaper. When the plants are dead, bury them or dispose of them with other green waste in accordance with Council by-laws.