Plant Gallery Red Lupine in well-drained, slightly acidic to neutral soil. Choose a location with full sun to partial shade. Space plants about 12-18 inches apart. Water regularly to keep the soil consistently moist but not waterlogged. Apply a balanced, slow-release fertilizer in early spring. Deadhead spent flowers to encourage more blooms. Cut back the plant after flowering to promote healthy growth. Protect from strong winds and provide support if necessary.