European blue lupine

European blue lupine is a vigorous annual or short-lived perennial legume that produces striking blue flower spikes attractive to bees and butterflies. It thrives in well-drained, slightly acidic soil in full sun to partial shade and is relatively low-maintenance once established, fixing nitrogen in the soil. Deadhead spent blooms to prolong flowering and be aware that seeds and foliage contain alkaloids that are toxic if ingested in large quantities.