Collared annual lupine
Lupinus truncatus
Last reviewed: September 2026
Collared annual lupine (Lupinus truncatus) is a annual forb native to CA. It blooms in March, April, and May. The flowers draw bumble bees and native bees.
Toxicity unknown
Collared annual lupine (Lupinus truncatus) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
full sun
Water
low
Size
8"–24" H × 8"–16" W
Bloom
Mar, Apr, May
Native to
CA
Pollinators
bumble bees, native bees
Before you buy
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Browse plants for this ecoregion
An upright annual with palmately compound leaves and a spike of pea-shaped, blue-purple flowers, each marked with a distinctive banner spot. Grows in grassland and dry, open slopes, often in large colorful stands in spring.
Growing Collared annual lupine
Grow Collared annual lupine in full sun and low water. Mature plants reach 8 to 24 inches tall and spread 8 to 16 inches wide.
Wildlife value
Host plant for Boisduval's blue.
The flowers are an important nectar source for bumble bees, and the foliage serves as a larval host plant for Boisduval's blue butterfly.
Common questions
- How much sun does Collared annual lupine need?
- Collared annual lupine grows best in full sun conditions.
- When does Collared annual lupine bloom?
- Collared annual lupine blooms in March, April, and May.
- Where is Collared annual lupine native?
- Collared annual lupine (Lupinus truncatus) is native to CA, per vouchered herbarium specimen records and regional native plant society lists.
- What butterflies or moths does Collared annual lupine host?
- Collared annual lupine is a larval host plant for Boisduval's blue.
Native range data from vouchered herbarium specimen records and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
If something looks wrong
Common plant problems, and what to check first
These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.
- It is dying right after planting
- Leaves turning yellow
- Wilting even though I watered it
- Brown crispy leaf tips
- Bugs on the plant
Ready to grow Collared annual lupine? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.