North America Native Plant

Trout Creek Milkvetch

Botanical name: Astragalus salmonis

USDA symbol: ASSA4

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Trout Creek Milkvetch: A Rare Native Gem for the Adventurous Gardener Meet Trout Creek milkvetch (Astragalus salmonis), one of those special native plants that makes you feel like you’ve discovered a botanical treasure. This perennial member of the pea family might not be the showiest plant in your garden, but ...

Rare plant alert!

Region: Conservation status by state

Status: S3S4: Status is uncertain but is somewhere between the following rankings: 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 ⚘

Trout Creek Milkvetch: A Rare Native Gem for the Adventurous Gardener

Meet Trout Creek milkvetch (Astragalus salmonis), one of those special native plants that makes you feel like you’ve discovered a botanical treasure. This perennial member of the pea family might not be the showiest plant in your garden, but it carries the distinction of being a true regional native with an important story to tell.

Where Does Trout Creek Milkvetch Call Home?

This distinctive milkvetch has a relatively small geographic footprint, naturally occurring in parts of Idaho, Nevada, and Oregon. It’s particularly associated with the Great Basin region, where it has adapted to thrive in some pretty challenging conditions that would make many garden plants throw in the towel.

A Plant Worth Protecting

Here’s something important every gardener should know: Trout Creek milkvetch has a Global Conservation Status of S3S4, which means its populations are showing some signs of concern. While it’s not critically endangered, this status suggests we should be thoughtful stewards when it comes to this species. If you’re interested in growing it, make sure you source plants or seeds responsibly from reputable native plant nurseries—never collect from wild populations.

What Makes This Milkvetch Special?

As a perennial, Trout Creek milkvetch offers several appealing qualities for the right garden setting:

  • Produces clusters of small, pea-like flowers typical of the Astragalus genus
  • Adapted to survive in drought conditions once established
  • Supports native pollinators, particularly native bees
  • Adds authentic regional character to native plant gardens
  • Requires minimal maintenance once established

Is Trout Creek Milkvetch Right for Your Garden?

This isn’t a plant for every garden or every gardener. Trout Creek milkvetch is best suited for:

  • Native plant enthusiasts who appreciate rare and specialized species
  • Rock gardens and xerophytic landscape designs
  • Drought-tolerant garden schemes
  • Educational or conservation-focused plantings
  • Gardens in or near its native range

If you’re looking for a low-maintenance groundcover or a plant that provides dramatic seasonal color, you might want to consider other native options that are easier to source and establish.

Growing Trout Creek Milkvetch Successfully

Like many plants adapted to arid conditions, this milkvetch can be a bit finicky about its growing requirements:

Essential Growing Conditions

  • Full sun exposure
  • Excellent drainage—soggy soil is a death sentence
  • Lean, rocky, or sandy soils
  • Minimal supplemental watering once established
  • Good air circulation

Planting and Care Tips

Getting Trout Creek milkvetch established requires patience and attention to detail. Plant in spring or fall, ensuring the soil drains quickly after rain or irrigation. Avoid rich, fertile soils that retain moisture—this plant actually prefers the tough love approach that mirrors its natural habitat.

Once established, resist the urge to pamper it with regular watering or fertilization. These plants have evolved to thrive on neglect, and too much care can actually harm them.

Supporting Conservation Through Gardening

By choosing to grow Trout Creek milkvetch responsibly, you’re participating in plant conservation efforts. This species represents the unique flora of the Great Basin region, and cultivating it helps preserve genetic diversity while creating habitat for native pollinators.

Just remember: always source your plants ethically, be patient with establishment, and appreciate the quiet beauty of this specialized native. It may not be the flashiest addition to your garden, but it’s certainly one of the most meaningful for supporting regional biodiversity.

Trout Creek 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 salmonis M.E. Jones - Trout Creek milkvetch

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