sainfoin
Onobrychis viciifolia · Fabaceae
sainfoin (Onobrychis viciifolia) is a perennial herbaceous plant in the Fabaceae family. It is introduced to North America rather than native. USDA records it as hardy in zone 3 and warmer, down to about -40°F.
At a glance
| Type | forb-herb USDA |
|---|---|
| Lifecycle | perennial USDA |
| Native status | introduced USDA |
| Mature height | 3 ft USDA |
| Light | full-sun USDA |
| Water need | medium USDA |
| Growth rate | moderate USDA |
| Soil pH | 6–8.5 USDA |
| Bloom | May–June USDA |
| Flower color | Red USDA |
| Hardiness zones | 3 and warmer USDA |
| Guild layer | nutrient Derived |
| Nursery availability | Routinely Available USDA |
USDA quoted from the USDA PLANTS database · Derived computed by a fixed rule from those columns. No value on this page is estimated.
Growing conditions
It needs full sun. USDA rates it as having moderate water needs. Its drought tolerance is rated medium. It will not tolerate waterlogged soil — USDA rates its anaerobic tolerance as none. It is recorded on soils from pH 6 to 8.5 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 3.
Size and growth
At maturity it reaches about 3 ft, making it roughly waist to chest height. It grows at a moderate rate.
Bloom period
USDA records a bloom period of May through June. Flowers are red.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is green, medium in texture. Its flowers are conspicuous. Its active growth period is spring and summer. USDA rates its lifespan as moderate.
What the site needs to provide
USDA records it across sites receiving 12 to 45 inches of annual precipitation. The low end of that band is genuinely arid, so it has a wide tolerance for dry country. It needs at least 90 frost-free days to finish its season. It roots to at least 14 inches. Fertility requirement: medium.
Propagating it
Seed is the only propagation method USDA lists. Division and cuttings are not listed as options. USDA records no cold-stratification requirement, so seed should germinate without a chilling period. Its seed spreads at a slow rate. It does not spread vegetatively, so it will stay where you put it.
Resilience and wildlife
Browsing animals find it moderately palatable, so expect deer and rabbits to take an interest. Its fire tolerance is rated low. Its growth form is recorded as single crown.
Role in a guild
Nutrient layer. In a layered planting this is it contributes to soil fertility rather than to structure. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Similar role and hardiness
- white prairie clover Dalea candida
- purple prairie clover Dalea purpurea
- Utah sweetvetch Hedysarum boreale
- sweetclover Melilotus officinalis
- common reed Phragmites australis
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol ONVI, or is computed from those values by a fixed rule. Nothing here is estimated or model-generated. Where USDA publishes no value, this page omits the claim rather than filling the gap.
- Quoted from USDA PLANTS: active growth period, Bloom, Bloom end, browse palatability, cold stratification, Drought tolerance, fall conspicuous, fertility requirement, fire tolerance, Flower color, flower conspicuous, foliage color, foliage porosity winter, foliage texture, frost free days min, fruit conspicuous, growth form, Growth rate, Hardiness zones, Lifecycle, lifespan, Light, Mature height, Minimum temperature, Native status, Nitrogen fixation, Nursery availability, precipitation max in, precipitation min in, propagation, resprout ability, root depth in, seed spread rate, Soil pH, Soil pH (upper), Tolerance of wet soil, Toxicity, Type, vegetative spread rate, Water need.
- Derived by a fixed rule from those columns: Guild layer.
Read our full data sources and methodology.
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