Goat’s rue

Scientific name: Galega officinalis
  • Key characteristics
  • Biology
  • Impacts
  • Control
  • Further information

  • Erect, hairless perennial with an annual growth habit, growing 1-2 m tall from a stout rootstock
  • Pinnate leaves with four to nine pairs of oval leaflets
  • Pea like flowers up to 13 mm long borne on many flowered spikes up to 30 cm long, usually pinkish-blue but sometimes deep pink, white, or pale purplish
  • Common as a weed mostly in the flood plain of the Manawatu River but slowly spreading or, rather, being spread in river shingle used for roads in the southern North Island
  • Found in river or stream beds, swampland, damp pastures, roadsides, railway lines and waste places
  • Can be poisonous to hungry travelling livestock (especially sheep) when they are exposed to large amounts of goat’s rue.

Origin and habitat

  • Native to Europe and parts of western Asia, including Russia
  • Supposedly introduced into New Zealand in stuffing in a mattress that was emptied into a tributary of the Manawatu River
  • In New Zealand first found in and around the Manawatu River but now slowly being observed further afield – in Taihape, Taranaki and parts of Wellington Province
  • Possibly being spread in road shingle taken from the Manawatu River or by roadside grading or mowing
  • In parts of the USA it is called professor weed because it was introduced by a university to test as a forage plant but its toxicity to livestock brought a halt to the testing. It is now a ‘federal noxious weed’
  • Plants are sometimes grown by herbalists
  • The species is considered a pest plant by some Regional Councils (see your local Council’s website for further information).


  • The seeds are in two to eight-seeded pods about 4 cm long. A single spike may contain up to 100 flowers and a single plant up to 150 flower spikes, thus producing  15,000 pods
  • The seeds can last for many years in the soil or in road shingle; seed numbers as high as 74,000 per square metre have been recorded under dense infestations in North America
  • Seeds germinate best if shallowly buried in the soil; when buried at depths of 12-14 cm no seedlings emerge
  • Plants develop a large, woody rootstock and seem to be able to survive for several years, sending up new shoots each year
  • Plants can tolerate quite severe frosts but generally die back each winter and quickly produce lush fresh growth each spring
  • Plants of goat’s rue form a symbiotic relationship with the bacterium Rhizobium galegae, which allows plants to fix nitrogen from the atmosphere.


  • Grown in its native region as a forage plant
  • Commonly used as a herbal remedy, primarily these days for its supposed ability to promote milk flow in both humans and livestock.

  • Cultivated as a forage plant in parts of Europe and Asia. No-one seems to know why it can be used safely there but is considered poisonous in countries to which it has been introduced.

Impact on pasture

  • Individual plants take up appreciable pasture space, displacing more valuable fodder species.

Impact on livestock

  • Under some circumstances can be toxic to livestock, especially sheep and goats
  • Its effects are probably worst when tired hungry sheep are allowed to graze in heavily-infested pastures or when being driven along roadsides.

Grazing management

  • Do not allow livestock, particularly sheep, to gorge themselves on goat’s rue, especially when they are tired and hungry.

Chemical control

  • Goat’s rue is best controlled by spot treatment with herbicides such as picloram or aminopyralid plus picloram. 2,4-D plus dicamba or glyphosate may also be effective