purple locoweed
Oxytropis lambertii · Fabaceae
purple locoweed (Oxytropis lambertii) is a perennial herbaceous plant in the Fabaceae family. It is native to North America. USDA records it as hardy in zone 3 and warmer, down to about -38°F.
At a glance
| Type | forb-herb USDA |
|---|---|
| Lifecycle | perennial USDA |
| Native status | native USDA |
| Mature height | 1.4 ft USDA |
| Light | full-sun USDA |
| Water need | low USDA |
| Growth rate | moderate USDA |
| Soil pH | 6.4–9 USDA |
| Bloom | April–May USDA |
| Flower color | Red USDA |
| Hardiness zones | 3 and warmer USDA |
| Guild layer | ground-cover Derived |
| Nursery availability | No Known Source 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 low water needs once established. 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 6.4 to 9 — a broad range that spans acidic through mildly alkaline ground. Its cold limit is zone 3.
Size and growth
At maturity it reaches about 1.4 ft, making it a low, mat-forming plant. It grows at a moderate rate.
Bloom period
USDA records a bloom period of April through May. Flowers are red.
A flowering date, not a pollinator rating.
Foliage, flower and season
Summer foliage is gray-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 16 to 24 inches of annual precipitation. It needs at least 90 frost-free days to finish its season. It roots to at least 10 inches. Fertility requirement: low — no feeding needed on ordinary garden soil.
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
Its fire tolerance is rated low. Its growth form is recorded as single crown.
Role in a guild
Ground cover. In a layered planting this is the lowest layer — it shades soil, holds moisture, and suppresses weeds. The layer is derived by a fixed rule from growth habit and mature height.
Tags
Related plants
Others in Oxytropis
- showy locoweed Oxytropis splendens
Similar role and hardiness
- Canadian milkvetch Astragalus canadensis
- buffalograss Bouteloua dactyloides
- mountain sedge Carex scopulorum
- downy paintedcup Castilleja sessiliflora
- analogue sedge Carex simulata
Where this data comes from
Every value on this page comes from the USDA PLANTS database record for symbol OXLA3, 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, 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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