Skip to main content
Lupinus albicaulis (Sicklekeel Lupine)
1 / 6
© L Ruiz, some rights reserved (CC-BY-SA) · GBIF

Lupinus albicaulis

Sicklekeel Lupine

Pacific Northwest and northern California

At a Glance

HabitUpright
FoliageDeciduous
Height1-4 feet (30-120 cm)
Width1-2 feet (30-60 cm)
Maturity3 years

Growing Zones

USDA Hardiness Zones

5 - 9
These zones indicate the coldest temperatures this plant can typically survive.
What's my zone? →
Frost Tolerancehardy

Overview

An erect herbaceous perennial reaching 1-4 feet (30-120 cm) tall from a woody crown and deep taproot. Leaves palmately compound with 7-9 linear-oblanceolate leaflets, 1-2.5 inches (2.5-6.5 cm) long, green above and silver-pubescent below. Stems clothed in dense appressed white hairs, the source of the species epithet albicaulis ('white-stemmed'). Inflorescences erect terminal racemes 4-12 inches (10-30 cm) long bearing 30-80 pea-like flowers. Flowers 0.5-0.6 inch (12-15 mm) long, pale violet to lavender or occasionally cream, with the keel petal sickle-shaped and pointing strongly upward, separating this species from related lupines. Fruits hairy pods 1-1.5 inches (2.5-4 cm) long containing 4-6 seeds; pods open explosively when dry, scattering seeds 3-6 feet (90-180 cm). Roots extend 4-5 feet (1.2-1.5 m) deep and fix nitrogen through Rhizobium nodules. Plants are short-lived perennials persisting 3-6 years. Leaves and seeds contain quinolizidine alkaloids; livestock losses have been documented from heavy grazing.

Native Range

Native to the western United States from southern British Columbia through Washington, Oregon, and northern California, east to Idaho. Found on dry open slopes, coniferous forest understory, and disturbed roadsides at 500 to 7,000 feet (150-2,100 m) elevation. Most abundant in second-growth forests and post-fire sites.

Suggested Uses

Commonly planted in dryland meadow plantings, native restoration projects, and pollinator-supporting gardens at 18-24 inch (45-60 cm) spacing. Self-seeding habit suits naturalistic plantings but may require thinning in formal settings. All parts contain quinolizidine alkaloids; livestock losses have been documented from heavy grazing in rangeland settings.

How to Identify

Distinguished from related Lupinus species by an upturned, strongly sickle-shaped keel petal pointing more vertical than horizontal, paired with white-pubescent stems. Leaflets 7-9 per leaf, narrower (3-5 mm wide) than the broader leaflets (6-10 mm) of L. polyphyllus. Flowers pale violet to lavender, smaller than those of L. arboreus. Pods densely hairy, not glabrous as in L. albifrons.

Appearance

Size & Dimensions

Height1' - 4'
Width/Spread1' - 2'

Reaches mature size in approximately 3 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~5 weeks
J
F
M
A
M
J
J
A
S
O
N
D
May through July depending on elevation; lowland and coastal populations flower from late May through June, montane populations through mid-July. Each raceme produces flowers for 2-3 weeks; the full bloom period in a stand extends 4-6 weeks.

Detailed Descriptions

Flower Description

pale violet to lavender, occasionally cream

Foliage Description

green above, silver-pubescent below

Growing Conditions

Sun Requirements

Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.0(Neutral)
357912
Soil Types
Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

2-3 years from seed to first bloom

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant container-grown specimens in autumn or direct-sow scarified seed in early spring. Established plants need water only during prolonged drought of more than 4 weeks; summer irrigation in warm climates causes root rot. Soils with active Rhizobium populations support nitrogen fixation; in new gardens, commercial pea/bean inoculant can be applied at planting. Aphid colonies appear on inflorescences in warm springs and disappear with summer heat. Powdery mildew develops in humid sites with restricted airflow but does not kill plants. Plants flower for the first time in year 2 or 3 from seed and decline after 4-6 years; self-sown seedlings replace mature plants in established stands.

Pruning

Cut spent racemes to the topmost set of leaves after flowering to encourage a second flush of bloom in late summer. Cut entire plant to 4 inches (10 cm) above the soil in late autumn after seed has dispersed; new growth emerges from the woody crown the following spring. Remove dead stems and litter at the base in winter to reduce overwintering aphid eggs.

Pruning Schedule

J
F
M
A
M
J
J
A
S
O
N
D
summerfall

Maintenance Level

low

Container Growing

Minimum container size: 3 gallons

⚠️ Toxicity Warning

Toxic to pets and humans