Equisetum spp.


Family: Equisetaceae

Origin: Various

Image of horsetail with yellow flowers.
Green stems have distinctive patches of white bands surrounded by black stripes. Mature stems are less than 1m tall.
Photo credit: Annie Lamb

Regional Pest Management Plan (RPMP) status

  • National Pest Plant Accord Species
  • Whole region — Sustained control

View more about the RPMP statuses

General description

Erect perennial fern allies. Rhizomes are extensive to < 1 m deep and tuberous. Stems are rush-like, erect and jointed. Spore cones are borne on the ends of fertile stems in spring.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell horsetail. As horsetail is a National Pest Plant Accord species, these restrictions apply within the Auckland region and across the whole of New Zealand.
  • You must not plant horsetail within the Auckland region, unless you are transferring an existing plant on your land to another location within the boundaries of the same property.
  • You must destroy any horsetail on land that you occupy if it has been planted in breach of the above rules and you are directed to do so by an authorised person.


Water body margins, wetlands, drains, croplands, roadsides, bare land.


Spores seldom produced in NZ. Vegetative spread from rhizomes, stem fragments and tubers, dispersed by water and soil movement. Human-mediated dispersal through contamination of machinery and deliberate plantings.

Impact on environment

Highly competitive in wetland and riparian margins, excludes other vegetation and alters nutrient cycles. Toxic to livestock.


Site Management

Follow up treated areas 3 times per year. Encourage natural regeneration of native plants or replant treated areas where possible after 2-3 treatments to establish dense ground cover and minimise reinvasion.

Recommended approaches

Physical control

Method: Dig out.

Plant parts requiring disposal: All parts.

Disposal options: Remove to greenwaste or landfill.


Biocontrol is currently not available for this species.

Community agrichemical control recommendations

No qualifications: Cut stump and paste freshly cut base of stems with metsulfuron gel. Remove stems to greenwaste or landfill.

Certified Handler/Experienced agrichemical user: Foliar spray with 5g metsulfuron-methyl per 10L of water and 20ml penetrant.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

Horsetail stems growing in grassy field.
A rush-like plant that has rhizomes that grow underground. Erect stems push up through the ground as the plant grows across a field.
Horsetail growing in gravel with clover.
Horsetail bears cones at the end of fertile stems, then producing spores. Mostly spread by rhizomes and stem fragments.
Photo credit: Annie Lamb
Horsetail stems growing in wild lotus field.
Likes to grow in wet areas and competes with native wetland species. Stems are toxic to livestock.
Photo credit: Annie Lamb