Formerly a popular garden plant, particularly in Europe, large-leaved lupin is an attractive addition to flower borders and cottage gardens and went on to be used as one of the parents of the famous Russell Hybrids that have dominated lupin-growing since the 1930s.
A stout herbaceous perennial, large-leaved lupin grows up to 1.5 m tall. The palmate leaves are divided into 9–17 leaflets; leaflets are up to 15×3 cm. Flowers can be blue, purple, pink or white and are up to 14 mm long. The pea-like flowers are arranged densely on stems up to 60 cm long. The fruit is a brown pod up to 4 cm long, covered with matted, woolly hairs; the pod opens to release 5–9 spotted seeds.
In addition to this general description of large-leaved lupin, it is important to note that the external form and appearance of this species is highly variable across its wide range in western North America.
It is commonly used in gardens for its attractiveness to bees, ability to improve poor sandy soils with their nitrogen fixing ability and flowers
Genus - Lupinus
Species - Polyphyllus
Common name - Bigleaf Lupine
Pre-Treatment - Not-required
Hardiness zones - 3 - 7
Height - 0.40 - 1 m
Spread - 0.40 - 0.60 m
Plant type - Perennial
Vegetation type - Deciduous
Exposure - Sun to Partial Shade
Growth rate - Fast
Soil PH - Acid and neutral soils and can grow in very acid soils
Soil type - Light (sandy), medium (loamy) and heavy (clay) soils, can grow in nutritionally poor soil.
Water requirements - Well-drained, moist soil, can tolerate drought.
Care level - Easy
Landscape uses - In gardens for its attractiveness to bees, ability to improve poor sandy soils with their nitrogen fixing ability
Germination rate - 95%
Bloom season - Summer
Leaf / Flower color - Green, blue - green / Blue, pink or violet