Lupinus mutabilis: complete guide

Overview

Lupinus mutabilis, also known as South American lupin, Andean lupin, or tarwi, is a spectacular flowering plant from South America. This dynamic plant produces beautiful, color-variable flower spikes.

Appearance & bloom

Lupinus mutabilis reaches 24 to 60 inches in height and grows upright. The plant has palmately divided leaves with 7 to 15 narrow leaflets. The flower spikes (racemes) are dense and elongated, reaching up to 30 cm long. Flowers vary in color from white to pink, purple, blue, yellow and orange. The flowering period runs from June to September.

Ideal location

Place Lupinus mutabilis in full sun to light shade. The plant grows best with at least 4-6 hours of direct sunlight. In very warm climates, light afternoon shade may be beneficial. Good ventilation reduces diseases.

Soil

Lupinus mutabilis grows best in well-draining, sandy soil with reasonable fertility. The plant tolerates various soil types but prefers slightly acidic to neutral soil (pH 5.5-7.0). Add sand for better drainage. Nitrogen-rich soil can reduce flowering.

Watering

Keep the soil consistently moist but not waterlogged. Water regularly during the growing season. Avoid excessive moisture which can lead to root rot and fungal diseases. Water more thoroughly during dry periods.

Pruning

Remove spent flowers or entire spikes to encourage more blooms. This stimulates side branch growth. After flowering, stems can be cut back almost completely.

Maintenance calendar

Spring: Plant seeds or young plants. Summer: Water regularly, remove spent flowers. Fall: Reduce watering, remove plant material. Winter: Minimal maintenance.

Winter hardiness

Lupinus mutabilis is frost-sensitive and grows best as an annual in most temperature zones. In milder climates it can overwinter with protection. Winter hardiness to approximately USDA zone 9.

Companion plants

Combine with other summer bloomers such as larkspur, delphiniums, or roses. Group at least 3 plants for dramatic effect. Lower plants work well in front.

Closing

Lupinus mutabilis is a splendid plant for colorful gardens and borders. Ideal as a cut flower. Perfect for garden design discussions on gardenworld.app/en.