Sainfoin
Onobrychis viciifolia
Botanical family: Fabaceae
Onobrychis viciifolia, a traditional fodder plant of chalky hillsides, is distinguished by its upright spikes of pink veined flowers. Long grown to feed livestock without risk of bloat (unlike alfalfa), it remains today a safe bet for flowering meadows and poor soils to be improved.
Full sun
Chalky, dry, even poor
Very low, a plant of dry meadow
Hardy perennial (several years of production)
Overwinters in your zone
Role in permaculture
A perennial Fabaceae with a deep taproot, sainfoin captures nitrogen from the air and thrives on the dry chalky soils where few fodder legumes establish. Its bright pink flowering feeds a great diversity of bees, bumblebees, and butterflies, which makes it a precious piece of flowering meadows.
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…”.
Sainfoin fixes atmospheric nitrogen by nodulating with a bacterium of its own, isolated and described from its nodules. The mechanism is demonstrated (nodulation, fixation, biomass gain in a greenhouse); the field magnitude is not measured in the primary study, and sainfoin fixes less than the major forage legumes.
scientific study
- · Ashrafi et al. (2022), Microbiology Spectrum, DOI 10.1128/spectrum.01099-22
Its pink racemes are a fine resource of nectar and pollen. An effectiveness measure (pollen deposited per visit) places the red-tailed bumblebee ahead of the honeybee for pollinating this plant: the most frequent visitor is not always the most effective. The absolute honey value in the garden is not reliably quantified.
scientific study
- · Gorenflo, Diekötter, van Kleunen, Wolters & Jauker (2017), Journal of Pollination Ecology 21, DOI 10.26786/1920-7603(2017)421
A livestock synergy, not a companion-planting one: the condensed tannins of sainfoin have an anthelmintic activity in livestock. Fed on sainfoin, calves see one species of intestinal parasite recede by about half, but the effect is PARTIAL (nil on another species, with no drop in excreted eggs). A real value as forage for ruminants; unrelated to neighbouring crops or to human health.
scientific study
- · Desrues O., Peña-Espinoza M., Hansen T.V.A., Enemark H.L., Thamsborg S.M. (2016), Parasites & Vectors 9:329, DOI 10.1186/s13071-016-1617-z
Seasons & availability
A perennial legume of dry limestone soils: sown in spring, February to May, or in late summer, August and September; the cover stands from spring to autumn, with pink, nectar-rich flowers from May to August.
Available: March, April, May, June, July, August, September, October.
Guidance for the oceanic / temperate climate; it may vary with your region, altitude, exposure and growing method.
Sources
- La Ferme de Sainte Marthe, « Réussir la culture du sainfoin : semis, culture et entretien » (fermedesaintemarthe.com/en/blogs/comment-reussir-la-culture-de/reussir-la-culture-du-sainfoin)
- Plants For A Future, « Onobrychis viciifolia » (pfaf.org/user/Plant.aspx?LatinName=Onobrychis+viciifolia)
Nutritional & medicinal properties
For educational purposes. Not a substitute for medical advice. Effects depend on the form, the dose and personal context.
Precautions & contraindications
A forage and honey-producing plant: no human food use.
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
Key takeaways
- • Prefers full sun exposure.
- • Ideal soil: chalky, dry, even poor.