Goat's rue (galega)
Galega officinalis L.
Botanical family: Fabaceae
A large perennial legume with pale-mauve flowers, nitrogen-fixing and nectar-bearing. A traditional fodder plant ('goat's rue'), it inspired the development of metformin.
Sun to partial shade
Cool, rich, tolerates moisture
Regular: a plant of damp meadows that copes well with wet soil
Very hardy
Overwinters in your zone
Role in permaculture
A perennial green manure: it fixes nitrogen to enrich the soil, while its long flowering feeds bees and bumblebees. It has also been grown as fodder. It can become invasive in some regions.
Insects attracted or useful
Documented synergies
Relationships backed by a named source, with their real scope. A synergy without a named reference has no place here, no “it is said that…”.
The galega fixes nitrogen, but with a symbiont of extreme specificity: it is nodulated ONLY by Neorhizobium galegae, absent from soils that have never carried this plant. Without co-introduction or inoculation of the right strain, it fixes no nitrogen, researchers even see it as a factor that limits its spread. Its agronomic reach in the garden is therefore low, and no reliable return figure is available.
scientific study
- · Bromfield E.S.P. et al. (2019), Ecology and Evolution 9(12):6999-7004, DOI 10.1002/ece3.5266
- · Darbyshire S.J. et al. (2022), Canadian Journal of Plant Science 102(1):160-185, DOI 10.1139/CJPS-2020-0327
A major safety point: the galega contains galegine, an alkaloid that can kill a sheep within hours (pulmonary oedema), with fatal cases actually reported in France. It's not a companion plant, it's an incompatibility: it cannot coexist with a pasture. Cattle often reject it (bitterness); the sheep is the most exposed, especially in drought when other forage is lacking.
scientific study
- · Keeler R.F., Baker D.C., Panter K.E. (1992), J Environ Pathol Toxicol Oncol 11(2):11-17, PMID 1573558
- · Puyt J.D. et al. (1981), Vet Hum Toxicol 23(6):410-412, PMID 7336561
To be handled with caution: the galega appears on regional lists of invasive alien species in France ('established invasive' in Rhône-Alpes). It colonises banks and wet meadows, its seeds travel by water and stay viable in the soil for at least eleven years. Combined with its toxicity, it degrades the value of meadows. Not to be sown near a watercourse.
institutional source
- · Darbyshire S.J. et al. (2022), Canadian Journal of Plant Science 102(1):160-185, DOI 10.1139/CJPS-2020-0327
- · Debay, P., Legland, T. & Pache, G. (2020). Liste actualisée et hiérarchisée des espèces exotiques envahissantes : bilan de la problématique végétale invasive en Rhône-Alpes. Conservatoire botanique national alpin.
- · Oldham, M. & Ransom, C.V. (2009). Goatsrue (Galega officinalis) Seed Biology. Weed Science, 57(2), 149-154.
- · Hadfield, J., Ransom, C., Zesiger, C. & Israelsen, C. (2021). Goatsrue (Galega officinalis) Identification and Management in Pastures and Croplands. Utah State University Extension.
Seasons & availability
Flowering tops cut in summer, then dried.
Available: January, February, March, April, May, June, July, August, September, October, November, December.
Guidance for the oceanic / temperate climate; it may vary with your region, altitude, exposure and growing method.
Sources
- Plants For A Future, « Galega officinalis » (pfaf.org/user/Plant.aspx?LatinName=Galega+officinalis)
- Tela Botanica, « Galega officinalis L. » (tela-botanica.org/bdtfx-nn-28730-description)
Nutritional & medicinal properties
For educational purposes. Not a substitute for medical advice. Effects depend on the form, the dose and personal context.
Precautions & contraindications
May lower blood sugar (caution with diabetes treatments); toxic to livestock in large quantity when fresh; internal use to be supervised, not advised during pregnancy.
Family behaviour: Legumes
In general, Legumes fix nitrogen from the air in most cases, thanks to the Rhizobium in their root nodules. They mainly enrich the soil for the following crops, as their residues decompose. Ideal in a rotation, before nitrogen-hungry plants such as nightshades.
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Species & varieties
The best-known species and varieties in France.
Common varieties
Regulatory status in Europe
A species' status varies from one country to another: check before growing, selling or foraging it outside France.
SwitzerlandCultivation prohibited
Prohibited from use and from being put into circulation (invasive alien species).
Ordonnance suisse sur la dissémination dans l'environnement (ODE, RS 814.911), annexe 2
Key takeaways
- • Prefers sun to partial shade exposure.
- • Ideal soil: cool, rich, tolerates moisture.