North America Native Plant

Santa Barbara Milkvetch

Botanical name: Astragalus trichopodus var. lonchus

USDA symbol: ASTRL

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Astragalus leucopsis (Torr. & A. Gray) Torr. & A. Gray (ASLE16)  âš˜  Astragalus trichopodus (Nutt.) A. Gray ssp. leucopsis (Torr. & A. Gray) Thorne (ASTRL2)   

Santa Barbara Milkvetch: A Rare Gem for California Native Gardens If you’re looking to add a truly special plant to your California native garden, the Santa Barbara milkvetch (Astragalus trichopodus var. lonchus) might just be the hidden treasure you’ve been seeking. This charming little perennial shrub brings both beauty and ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4T3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals ⚘ Subspecies or variety is vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals. ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Santa Barbara Milkvetch: A Rare Gem for California Native Gardens

If you’re looking to add a truly special plant to your California native garden, the Santa Barbara milkvetch (Astragalus trichopodus var. lonchus) might just be the hidden treasure you’ve been seeking. This charming little perennial shrub brings both beauty and conservation value to the right garden setting.

What Makes Santa Barbara Milkvetch Special?

Santa Barbara milkvetch is a low-growing perennial shrub that stays compact and manageable, typically reaching just 1.5 feet tall and rarely exceeding 3 feet at maturity. Its delicate purple to pink pea-like flowers create a lovely display against silvery-green compound leaves, offering a subtle yet appealing aesthetic that perfectly complements other native California plants.

A True California Native

This plant is authentically Californian, native to the lower 48 states with its home range specifically in California’s coastal regions around the Santa Barbara area. It’s perfectly adapted to the Mediterranean climate and growing conditions that define much of coastal California.

Important Conservation Considerations

Here’s something every responsible gardener should know: Santa Barbara milkvetch has a Global Conservation Status of S3S4T3?, indicating it has some level of rarity or conservation concern. If you decide to grow this plant, it’s crucial to source it only from reputable native plant nurseries that propagate their stock responsibly rather than collecting from wild populations.

Garden Design and Landscape Role

Santa Barbara milkvetch shines in several garden settings:

  • Rock gardens where its compact size won’t overwhelm other plants
  • Native California plant collections
  • Drought-tolerant landscapes
  • Mediterranean-style gardens
  • Ground cover applications in appropriate climates

Growing Conditions and Care

Like many California natives, Santa Barbara milkvetch appreciates well-draining soil and full sun exposure. Once established, it’s quite drought-tolerant, making it an excellent choice for water-wise gardening. It thrives in USDA hardiness zones 9-10, which aligns perfectly with its native coastal California range.

Planting and Care Tips

Success with Santa Barbara milkvetch comes down to mimicking its natural habitat:

  • Plant in fall to allow root establishment during the rainy season
  • Ensure excellent drainage – this plant doesn’t tolerate soggy conditions
  • Provide minimal supplemental water once established
  • Avoid overwatering, which can lead to root problems
  • Choose a sunny location for best flowering

Benefits for Pollinators and Wildlife

As a member of the legume family, Santa Barbara milkvetch produces flowers that are particularly attractive to native bees and butterflies. By including this plant in your garden, you’re supporting local pollinator populations while contributing to the conservation of a rare California native species.

The Bottom Line

Santa Barbara milkvetch is a wonderful choice for gardeners who want to grow something truly special while supporting conservation efforts. Its compact size, attractive flowers, and low-maintenance nature make it a great addition to the right garden. Just remember to source it responsibly and provide the well-draining, sunny conditions it needs to thrive. Your garden – and California’s native plant heritage – will benefit from this charming little shrub.

Santa Barbara Milkvetch

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Astragalus L. - milkvetch

Species

Astragalus trichopodus (Nutt.) A. Gray - Santa Barbara milkvetch

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA