Lupinus arboreus (tree lupin) — Shrub

Overview

Lupinus arboreus is a shrub in the genus Lupinus, part of the Q44448 family. It typically grows around 1.5 m tall. Lupinus arboreus grows best in full sun, and tolerates sandy and loamy soils. Its UK hardiness is rated H5. Suggested uses include coastal gardens and wildlife gardens. It is native to W USA.

About

Lupinus arboreus is a shrub reaching about 1.5 m, producing fragrant summer flowers from June to August. It is native to the west coast of the United States and suits south-facing, sheltered sites in the UK. It prefers full sun and sandy to loamy, well-drained soils and is rated H5 (hardy) for UK conditions. Harmful if eaten — wear gloves and other protective equipment when handling, and note it is toxic to pets if ingested.

Wikipedia contributors, CC BY-SA 4.0 — Lupinus arboreus

About the genus

Lupinus, commonly known as lupin, lupine, or regionally bluebonnet, is a genus of plants in the legume family Fabaceae. The genus includes over 199 species, with centres of diversity in North and South America. Smaller centres occur in North Africa and the Mediterranean.

Wikipedia contributors, "Lupinus", CC BY-SA 4.0 — Lupinus

In the garden

Lupinus arboreus is a shrub from the west coast of the United States that forms a compact, flowering plant of roughly 1.5 m. Its summer display runs from June to August and the blooms are scented, so place it where the fragrance can be enjoyed. It favours full sun and will perform best in sandy or loamy soils that drain freely or remain moist but well-drained; exposure should be sheltered and a south-facing aspect helps ripen growth and flowers. Plant in a position protected from strong, cold winds to suit its sheltered exposure, and allow room for its mature height when siting near patios or mixed shrub borders. It carries a UK hardiness rating of H5 (hardy), so it tolerates ordinary winter conditions in most UK gardens provided the site is not overly exposed. Recommended uses include coastal gardens and wildlife gardens where a south-facing, sheltered nook is available. Take care handling plants: they are harmful if eaten, and toxic to pets if ingested, so wear gloves and other protective equipment during planting and pruning. For best effect, position Lupinus arboreus where its scented summer flowers can be experienced from a south-facing patio.

Growing conditions

Best soil and position for Lupinus

Sunlight: Full sun
Soil type: Sandy, Loamy
Soil moisture: Well-drained, Moist but well-drained
Aspect: South-facing
Exposure: Sheltered
UK hardiness: H5

Plant details

Lupinus arboreus size, habit and characteristics

Plant type: Shrub
Height: 1.5 m
Suggested uses: Coastal gardens, Wildlife gardens
Native to: W USA
Fragrance: Flower
Toxicity: Harmful if eaten. Wear gloves and other protective equipment when handling. TOXIC to pets if eaten (dogs, cats, rabbits, tortoises) - see the HTA guide to potentially harmful plants for further information and useful contact numbers

Care notes

Pruning and caring for Lupinus arboreus

Cultivation: Prefers sandy, well-drained soil; drought tolerant once established; avoid heavy clay soils
Pruning: Prune after flowering to maintain shape and encourage bushiness
Propagation: Seed, Cuttings

Frequently asked questions

How do I grow Lupinus arboreus?

Prefers sandy, well-drained soil; drought tolerant once established; avoid heavy clay soils.

Where is the best place to plant Lupinus arboreus?

Lupinus arboreus prefers full sun. It suits sheltered positions.

What soil does Lupinus arboreus need?

Lupinus arboreus grows best in sandy and loamy soil. Aim for soil that stays well-drained to moist but well-drained.

How do I prune Lupinus arboreus?

Prune after flowering to maintain shape and encourage bushiness.

How big does Lupinus arboreus grow?

Lupinus arboreus reaches a height of 1.5 m.

Is Lupinus arboreus hardy in the UK?

Lupinus arboreus has an RHS hardiness rating of H5, meaning it is hardy in most of the UK, tolerating -15 to -10°C.

How do I propagate Lupinus arboreus?

Seed, Cuttings.

Is Lupinus arboreus toxic?

Harmful if eaten. Wear gloves and other protective equipment when handling. TOXIC to pets if eaten (dogs, cats, rabbits, tortoises) - see the HTA guide to potentially harmful plants for further information and useful contact numbers.

More in the Lupinus genus

Browse all Lupinus →