• Key characteristics
  • Biology
  • Impacts
  • Control
  • Further information

  • Small, rosette-based annual up to 25 cm tall
  • Leaves are deep green, lobed and sparsely hairy. Each leaf has two or three pairs of rounded leaflets with a larger terminal lobe
  • Upright flower stems carry few leaves and many tiny white flowers in small clusters
  • Flowers are 4-5 mm across with four petals, each twice as long as the four sepals, and four stamens with yellow anthers
  • Flowers are followed by small, slender, upright pods 15-25 mm long. Two valves split explosively and coil upwards, spreading the seeds up to a metre from the parent plant.

Similar species

  • Wavy bitter cress (Cardamine flexuosa) is similar but often slightly larger with a wavy erect stem and six stamens in the flower. It is scattered throughout New Zealand and found in wetter environments than bitter cress
  • The native New Zealand bitter cress (Cardamine debilis) is similar to bitter cress but has larger flowers, each with six stamens. It is found throughout New Zealand, in a range of forest or tussock habitats
  • Cuckoo cress (Cardamine pratensis) is a rhizomatous perennial herb up to 60 cm tall. It has larger pink flowers and is found in wet places and along river banks in Northland, Auckland, Waikato, Manawatu and Horowhenua in the North Island and in Westland and Southland in the South Island.


  • Originally from Europe and western Asia, bitter cress has now been introduced to North America, eastern Asia, Australia and New Zealand
  • First recorded in New Zealand in 1901.

Life cycle

  • Flowers August to December. Plants can set seed within a few weeks of germinating, so several generations can occur in a year
  • One plant can produce up to 5000 seeds that can germinate immediately. However, if the seeds are in environments that do not favour germination they can survive for several years
  • Seeds are small and sticky when wet so can stick to footwear, enabling them be transported and dispersed
  • In a moist environment bitter cress can probably germinate, grow and set seed at any time of the year.


  • Leaves have a hot, cress-like flavour and have been used as a garnish or flavouring in salads.


  • Now found throughout the North Island and in eastern areas of the South Island, as well as on Stewart and Chatham Islands
  • Commonly found in damp gardens, along driveways, in cultivated or disturbed ground and can also be found growing in plant pots.

  • Bitter cress is probably not very competitive as a weed although if many individual plants germinate together they could limit the growth of later germinating species
  • Seeds generally do not germinate in the presence of competitive or shading vegetation such as pasture
  • Plants can act as hosts for common garden pests such as aphids
  • Wavy bitter cress is more abundant in Poverty Bay and has been noted as a weed of arable crops in that region.

Impacts on pasture

  • Bitter cress is rarely a pasture weed although it could interfere with establishment of a new pasture if present in high numbers
  • Young stems with their soft, finely-divided leaves break easily but later become tougher and can sprawl for long distances.

Cultural control

  • Hand weeding is very effective but must be repeated regularly, preferably before the plants set seed. Individual plants are easy to dislodge and uproot. Uprooted fruiting plants can continue shedding seed.
  • Bitter cress is usually found in open places and the seeds probably don’t germinate under the cover of vegetation.
  • Bitter cress also germinates from very close to the surface (less than 10 mm deep) and will not grow if the soil surface is dry. It germinates best in compacted, damp soils.

Chemical control

  • Bitter cress (Cardamine hirsuta) is readily controlled by a wide range of herbicides including 2,4-D, glyphosate and many of those normally used in crop production.

  • Popay I, Champion P, James T 2010. An illustrated guide to common weeds of New Zealand. New Zealand Plant Protection Society, Christchurch, New Zealand. 416 p.