Lupinus rivularis (Riverbank Lupine)
Riverbank Lupine, Riverside Lupine, Streambank Lupine, Stream Lupine, Nine Finger, Lupinus lignipes, Lupinus amphibium
Noted for its showy floral display and pleasant fragrance, Lupinus rivularis (Riverbank Lupine) is a showy annual, biennial, or short-lived perennial boasting elongated clusters of purple-blue to white pea-like flowers from early spring to mid-summer, depending on latitude and elevation. Lasting for about 2-4 weeks, the ravishing blossoms are borne atop tall, unbranched stems, well above the elegant foliage of palmately compound leaves. The flowers provide pollen and nectar for bumblebees and other native pollinators and beneficial insects. They are followed by sparsely hairy seed pods containing 6-10 seeds. Several species of birds use the seed for food. Birds, rabbits, and other small game use the abundant stems for cover. Riverbank Lupine grows from a deep taproot that penetrates the soil to a great depth (up to 5 ft.). It typically occurs in well-drained, sandy soils in British Columbia, west of the Cascades in Oregon and Washington, and in northwestern California below 500 m (1600 ft). Fast-growing, Riverbank Lupine is an excellent pioneer species for disturbed areas, helping with erosion control. It can also facilitate the establishment of grasses and other wildflowers in restoration seedlings due to its ability to add nitrogen to the soil. It thrives on soils where other plants struggle, such as on sand dunes or roadside slopes.
- Grows up to 1-5 ft. tall (30-150 cm).
- Thrives in full sun in sandy or gravelly, well-drained soils. Best on soils low in nitrogen, such as sand dunes, cut slopes along roadsides, or dredge spoils, where competition is reduced.
- Propagated by seed. The seed should be scarified or soaked in hot water (180°F) to overcome physical dormancy and enhance germination rates.
- All parts, particularly the seeds, may cause severe discomfort if ingested. Toxic only if eaten in large quantities. Wear gloves and wash your hands after handling.
- Toxic to dogs, toxic to cats, toxic to horses, toxic to humans.
- Native to California, Oregon, Washington, and British Columbia.
Requirements
| Hardiness |
7 - 9 |
|---|---|
| Climate Zones | 4, 5, 15, 16, 17, 24 |
| Plant Type | Annuals, Perennials |
| Plant Family | Leguminosae |
| Genus | Lupinus |
| Exposure | Full Sun |
| Season of Interest |
Spring (Early, Mid, Late) Summer (Early, Mid) |
| Height |
1' - 5' (30cm - 150cm) |
| Maintenance | Low |
| Water Needs | Average |
| Soil Type | Loam, Sand |
| Soil pH | Acid, Alkaline, Neutral |
| Soil Drainage | Well-Drained |
| Characteristics | Fragrant, Showy |
| Native Plants | California, Oregon, Pacific Northwest, United States, Washington |
| Attracts | Bees, Birds, Butterflies |
| Garden Uses | Banks And Slopes |
| Garden Styles | Informal and Cottage, Prairie and Meadow |
Alternative Plants to Consider
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Requirements
| Hardiness |
7 - 9 |
|---|---|
| Climate Zones | 4, 5, 15, 16, 17, 24 |
| Plant Type | Annuals, Perennials |
| Plant Family | Leguminosae |
| Genus | Lupinus |
| Exposure | Full Sun |
| Season of Interest |
Spring (Early, Mid, Late) Summer (Early, Mid) |
| Height |
1' - 5' (30cm - 150cm) |
| Maintenance | Low |
| Water Needs | Average |
| Soil Type | Loam, Sand |
| Soil pH | Acid, Alkaline, Neutral |
| Soil Drainage | Well-Drained |
| Characteristics | Fragrant, Showy |
| Native Plants | California, Oregon, Pacific Northwest, United States, Washington |
| Attracts | Bees, Birds, Butterflies |
| Garden Uses | Banks And Slopes |
| Garden Styles | Informal and Cottage, Prairie and Meadow |
