Bigleaf Lupine (Lupinus polyphyllus) is a large perennial lupine recognized for its tall, showy spikes of dense flowers and lush, palmate leaves. Native to the western United States, it thrives in moist meadows, streambanks, and open forest edges, where its deep roots help stabilize soil. This lupine is particularly valued in restoration projects because, like other legumes, it fixes atmospheric nitrogen through root nodules that store beneficial bacteria, enriching soils and benefiting neighboring plants. 
 
The flower spikes, which can range in color from sky blue to purple, rise above dense foliage in late spring through summer. These blooms are highly attractive to native bees, butterflies, hummingbirds, and bumblebees (who are specifically adapted for accessing the flowers). Bigleaf Lupine also serves as a larval host plant for several butterfly species. The root exudates of Bigleaf Lupine have also been shown to render soil nutrients more readily available to other native plants, while also potentially improving native plant community resilience to nonnative invasive species.
 
In cultivation, Bigleaf Lupine prefers moist, well-drained soils with full sun to part shade. It is adaptable but performs best in cool, temperate climates and can naturalize readily under the right conditions. Germination requires special attention: seeds benefit from scarification (lightly nicking or sanding the hard seed coat) followed by a period of cold-moist stratification to break dormancy. This process ensures higher and more uniform germination success.