Practical
Plants

Lupinus arboreus

Tree Lupin

a perennial woody evergreen member of the Lupinus genus in the family Leguminosae.

No photo available

Taxonomy and growth

Genus
Lupinus
Life cycle
perennial
Foliage
evergreen
Woodiness
woody
Growth rate
vigorous
Height
1.5 m
Spread
1.2 m
Fertility
Bees
Flower type
hermaphrodite
Pollinators
Bees

Uses

Toxicity

Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.

This section contains historical Plants For A Future notes marked noncommercial.

The seed of many lupin species contain bitter-tasting toxic alkaloids, though there are often sweet varieties within that species that are completely wholesome[12][13]. Taste is a very clear indicator. These toxic alkaloids can be leeched out of the seed by soaking it overnight and discarding the soak water. It may also be necessary to change the water once during cooking. Fungal toxins also readily invade the crushed seed and can cause chronic illness[12].

Material uses

This section contains historical Plants For A Future notes marked noncommercial.

A bright yellow dye is obtained from the flowers[3]. The root fibres have been used to make a string for making nets etc[11]. Plants are used in land reclamation schemes to stabilize sandy soils and dunes[8]. Because they are fast growing and tolerant of maritime exposure, they quickly provide shelter for other plants as well as enriching the soil with nitrogen[K]. An excellent pioneering plant in permaculture, even in exposed areas it grows rapidly to its maximum height of about 1.5 metres and will give shelter to enable other less tolerant plants to become established. It is especially useful for helping the establishment of shrubs and herbaceous perennials in small gardens[K].

Product or use
Dye
Product or use
String

Ecology and functions

Pioneer

Soil builder

Nitrogen fixer

Environment

Range
South-western N. America - California to Oregon. Naturalized in S. England.
Habitat
Stable sand dunes, coastal scrub and pine forest close to the coast. Naturalized by the sea in S. England[5].
Light
full sun
Shade tolerance
no shade
Water
moderate
Hardiness
Zone 8+
Soil textures
sandy, loamy
Soil pH
acid, neutral, alkaline
Drainage
well drained
Tolerances
high wind, maritime exposure, drought
Wind
Yes
Maritime
Yes
Tolerates Nutritionally Poor Soil
No
Drought
tolerant

Propagation

This section contains historical Plants For A Future notes marked noncommercial.

Pre-soak the seed for 24 hours in warm water and then sow in early spring in a greenhouse[1][8]. Germination should take place within a couple of weeks. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in early summer. It should also be possible to sow the seed in situ in mid to late spring. Protect the seed from mice. Cuttings of short side-shoots with a heel, July/August in a frame[2].

Cultivation

This section contains historical Plants For A Future notes marked noncommercial.

Requires a well-drained dry or moist soil in a sunny position[2][4]. Prefers an alkaline soil[6]. Grows well near the coast[2], resisting maritime exposure. Established plants are drought tolerant[7]. Plants can be grown in quite coarse grass, which can be cut annually in the autumn[9]. Hardy to about -15°c[5][8]. Plants are hardy in all but severe winters in Britain[8], though they become less hardy with age[2]. A fast-growing but short-lived plant[4], especially when growing in rich soils[2]. Plants have reached 2.7 metres tall and wide within 4 years from seed in a rich soil, flowering and producing seed prolifically[2]. Plants self-sow when in a suitable position[8]. The flowers bear the fragrance of white clover[10]. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[8].

References

  1. F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00

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  2. Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 1981-00-00

    ↩1↩2↩3↩4↩5↩6

  3. Grae. I. Nature's Colors - Dyes from Plants. MacMillan Publishing Co. New York. 1974-00-00 ISBN 0-02-544950-8

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  4. Thomas. G. S. Ornamental Shrubs, Climbers and Bamboos. Murray 1992-00-00 ISBN 0-7195-5043-2

    ↩1↩2

  5. Phillips. R. & Rix. M. Shrubs. Pan Books 1989-00-00 ISBN 0-330-30258-2

    ↩1↩2

  6. Brickell. C. The RHS Gardener's Encyclopedia of Plants and Flowers Dorling Kindersley Publishers Ltd. 1990-00-00 ISBN 0-86318-386-7

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  7. Chatto. B. The Dry Garden. Dent 1982-00-00 ISBN 0460045512

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  8. Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5

    ↩1↩2↩3↩4↩5↩6

  9. Thomas. G. S. Perennial Garden Plants J. M. Dent & Sons, London. 1990-00-00 ISBN 0 460 86048 8

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  10. Genders. R. Scented Flora of the World. Robert Hale. London. 1994-00-00 ISBN 0-7090-5440-8

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  11. Moerman. D. Native American Ethnobotany Timber Press. Oregon. 1998-00-00 ISBN 0-88192-453-9

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  12. Frohne. D. and Pf�nder. J. A Colour Atlas of Poisonous Plants. Wolfe 1984-00-00 ISBN 0723408394

    ↩1↩2

  13. Cooper. M. and Johnson. A. Poisonous Plants in Britain and their Effects on Animals and Man. HMSO 1984-00-00 ISBN 0112425291

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