
Lupinus polyphyllus
Lupinus polyphyllus
Safety & Hazards
Lupinus species in general (and especially the seeds) contain a range of bitter-tasting alkaloids such as lupine, anagyrine, sparteine and hydroxylupanine. The pharmacological effects of these alkaloids are that they block ganglionic transmission, decrease cardiac contractility and contract uterine smooth muscle[1]. When ingested in moderate to large quantities they can cause symptoms such as respiratory depression and slow heartbeat, sleepiness and convulsions[2]. Alkaloid levels can vary greatly from species to species, and several members of the genus are used for food. In some species low-alkaloid, sweeter-tasting varieties have been developed. There are also techniques (particularly soaking and discarding the soak water) that lower the alkaloid levels. Unless it is known that the plant is low in alkaloids then caution should be applied to any ingestion of the plant[PFAF]. Fungal toxins can readily invade the crushed seed and can cause chronic illness[3].
Cultivation Details
Lupinus polyphyllus is a very cold-hardy plant, able to tolerate temperatures down to around -35°c when fully dormant[4]. An easily grown plant, succeeding in any moderately good soil in a sunny position[5, 4]. It strongly dislikes excessive winter wet[5]. Requires an acid to neutral soil[4]. Succeeds in poor soils[6]. Members of this genus are mainly found in dry habitats, often on stony and low fertility soils[4]. This species, however, is more common on moister, but well-drained, soils[4]. Plants can be naturalized in the wild garden, especially on stream banks and for flowering above rough grass, where they may be short-lived but will self-seed[4]. Plants dislike root disturbance. There are some named varieties, selected for their ornamental value[4]. The plants often do not flower in their first year from seed, but then generally flower freely[7]. The flowers are pleasantly scented[7]. Plants often become dormant in late summer, producing new shoots in early spring[7]. 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[4].
Propagation
Pre-soak the seed for 24 hours in warm water and then sow in early spring in a greenhouse[5, 4]. The seed is best sown in individual pots since the plants strongly resent root disturbance. Germination should take place within a couple of weeks. If sown in trays, then the seedlings should be potted up into individual pots as soon as they are large enough to handle. Plant out in early summer when the plants are around 15cm tall. It should also be possible to sow the seed in situ in mid to late spring. Protect the seed from mice. Basal cuttings, mid spring in a cold frame. Harvest the shoots when they are about 10cm long with plenty of underground stem. Pot them up in a very sandy soil in individual pots and keep them in light shade in a cold frame or greenhouse until they are rooting well. Plant them out in the summer. Division in early spring. Difficult. Lupin propagation is usually carried out by seed - vegetative propagation is normally only used when propagating named cultivars[4]. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Lupinus+polyphyllus>
Pollinators
Bees, Insects
References
- [1]Protabase - Plant Resources of Tropical Africa. — http://www.prota.org ↩︎An excellent on-line database with detailed information on over 3,200 species of useful plants of Africa.
- [2]Poisonous Plants of North Carolina — http://www.ces.ncsu.edu/depts/hort/consumer/poison/poison.htm ↩︎An excellent concise but comprehensive guide to toxic plants that grow in N. Carolina. It lists even those plants that are of very low toxicity, including several well-known food plants such as carrots and potatoes.
- [3]A Colour Atlas of Poisonous Plants. — Frohne. D. and Pfänder. J. · Wolfe · 1984 · ISBN 0723408394 ↩︎Brilliant. Goes into technical details but in a very readable way. The best work on the subject that I've come across so far.
- [4]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
- [5]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
- [6]Vascular Plants of the Pacific Northwest. — Hitchcock. C. L. · University of Washington Press · 1955 · ISBN - ↩︎A standard flora for Western N. America with lots of information on habitat etc. Five large volumes, it is not for the casual reader.
- [7]Plants Database — United States Department of Agriculture · http://plants.usda.gov/java/factSheet ↩︎An online database with an excellent collection of fact sheets about native N. American plants.
- [8]Flora of California — http://www.calflora.org ↩︎An on-line database of the Californian flora, giving details on plant habitats and photos of the plants.
- [9]Native American Ethnobotany — Moerman. D. · Timber Press. Oregon. · 1998 · ISBN 0-88192-453-9 ↩︎Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
- [PFAF]Plants for a Future — pfaf.org ↩︎