Menyanthes trifoliata


Also known as:


Family: Menyanthaceae

Origin: Eurasia, North America

A collecting of three leaved bogbean stalks with small hairy white flowers.
Bogbean is a sprawling perennial herb. Flowers are pinkish-white, 2.5 cm across and have five petals.
Photo credit: Trevor James, Agresearch

Regional Pest Management Plan (RPMP) status

  • National Pest Plant Accord Species

View more about the RPMP statuses

General description

Short, mat-forming, rhizomatous perennial aquatic herb. Leaves are light green, hairless, alternate and in groups of three. Flowers are small, white, star-shaped and borne in clusters on erect stems in October-April. Seeds are round and orange.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell bogbean. As bogbean is a National Pest Plant Accord species, these restrictions apply within the Auckland region and across the whole of New Zealand.


Riparian and lake margins, ponds, wetlands.


Sets seed. Vegetative spread from stem extension, rhizomes and stem fragments.

Impact on environment

Grows rapidly and clogs waterways.


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: Stems and roots.

Disposal options: Compost stems and roots in a composting weed bag or remove to greenwaste or landfill. Cover terrestrial sites with black plastic or weedmat for 6 to 12 months.


Biocontrol is currently not available for this species.

Community agrichemical control recommendations

Basic Growsafe certified:

For small infestations on terrestrial sites: Foliar spray with 0.5g metsulfuron-methyl per 1L of water.

For small infestations on aquatic sites: Foliar spray with 20ml glyphosate green per 1 L of water.

Certified Handler/Experienced agrichemical user:

For medium to large infestations on terrestrial sites: Foliar spray with 5g metsulfuron-methyl per 10L of water and 20ml penetrant.

For medium to large infestations on aquatic sites: Foliar spray with 200ml glyphosate green per 10L of water.

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

Photo showing the bogbean plant in the water.
Flowers are small, white and star-shaped.
Photo credit: Photographer: Paul Champion, Date taken: 29 August 2001, Licence: All rights reserved.
Photo of the thick stands of bogbean in water.
Bogbean creates thick stands.
Photo credit: