Tree lupine

Profile

Family

Fabaceae

Habit

Shrub

Height

1.5 m

Spread

1.2 m

Growth

very fast

Lifespan

6 years

First yield

after 2 years

Hardiness

zone 8–11

Shade tolerance

full sun

Soil

Sand, Silt

Soil moisture

dry – very moist

pH

5 – 7.5

Synonyms

Buschlupine

Flowering & harvest

Times apply to the northern hemisphere in a temperate climate and shift with altitude and cultivar.

Uses

Other uses: A bright yellow dye is extracted from the flowers. The root fibers were used to make cords for nets, among other things. These plants are utilized in land reclamation programs to stabilize sandy soils and dunes. Due to their rapid growth and good tolerance to the marine environment, they quickly provide protection for other plants and enrich the soil with nitrogen. Serving as an excellent pioneer plant in permaculture, it rapidly grows to its maximum height of about 1.5 meters in exposed areas, offering protection for the establishment of other, less tolerant plants. It is particularly suitable for planting shrubs and perennials in small gardens.

Growing

Requires well-drained, dry or moist soil in a sunny location. Prefers alkaline soil. Thrives near the coast and tolerates maritime influences. Established plants are drought-resistant. Can grow in fairly coarse grass that can be cut annually in the autumn. Hardy to about -15°C. Plants are hardy in all winters except severe ones, but lose winter hardiness with age. A fast-growing but short-lived plant, especially in nutrient-rich soils. In nutrient-rich soils, plants have reached a height and width of 2.7 meters from seed within 4 years, blooming and producing abundant seeds. Plants self-seed at a suitable site. The flowers smell like white clover. This species lives in symbiosis with specific soil bacteria, forming nodules on the roots and fixing atmospheric nitrogen. Some of this nitrogen is used by the growing plant itself, while another part can be utilized by other plants nearby.

Propagation

Soak the seeds in warm water for 24 hours and sow them in early spring in a greenhouse. Germination should occur within a few weeks. Once the seedlings are large enough, transplant them into individual pots and plant them out in early summer. Direct sowing is possible in mid to late spring. Protect the seeds from mice. Take cuttings from short side shoots with a heel, in July/August.

Origin & habitat

Southwestern North America - California to Oregon. Naturalized in southern part of England.

Derived in cultivation, likely from Ipomoea trifida, this species is not found in a completely wild environment.

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