North America Native Plant

Silver’s Milkvetch

Botanical name: Astragalus subcinereus

USDA symbol: ASSU6

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Astragalus silerianus M.E. Jones (ASSI11)  âš˜  Astragalus silerianus M.E. Jones var. cariacus (ASSIC)  âš˜  Astragalus subcinereus A. Gray var. basalticus S.L. Welsh (ASSUB)  âš˜  Astragalus subcinereus A. Gray var. silerianus (M.E. Jones) S.L. Welsh (ASSUS4)   

Silver’s Milkvetch: A Hardy Native Beauty for Water-Wise Gardens If you’re looking for a tough, drought-tolerant native plant that doesn’t skimp on charm, let me introduce you to Silver’s milkvetch (Astragalus subcinereus). This scrappy little perennial might not be the flashiest flower in the garden center, but it’s exactly the ...

Rare plant alert!

Region: Conservation status by state

Status: S3?T1Q: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Uncertain taxonomy: ⚘ Subspecies or variety is critically Imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 5 or fewer occurrences or very few remaining individuals (<1,000) ⚘ 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 ⚘ 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 ⚘

Region: Conservation status by state

Silver’s Milkvetch: A Hardy Native Beauty for Water-Wise Gardens

If you’re looking for a tough, drought-tolerant native plant that doesn’t skimp on charm, let me introduce you to Silver’s milkvetch (Astragalus subcinereus). This scrappy little perennial might not be the flashiest flower in the garden center, but it’s exactly the kind of reliable, low-maintenance native that smart gardeners are learning to love.

Meet Silver’s Milkvetch

Silver’s milkvetch goes by the botanical name Astragalus subcinereus, and you might occasionally see it listed under some older scientific names like Astragalus silerianus. This hardy perennial is a true native of the American Southwest, calling the rugged landscapes of Arizona, Nevada, and Utah home.

As a native plant, Silver’s milkvetch has spent thousands of years adapting to the challenging conditions of the southwestern United States. This means it’s naturally equipped to handle drought, poor soils, and temperature extremes that would send many garden center darlings running for cover.

What Makes Silver’s Milkvetch Special?

Don’t let the humble appearance fool you – this plant brings several wonderful qualities to your garden:

  • Beautiful purple to violet flowers arranged in attractive clusters
  • Silvery-gray foliage that provides lovely contrast in the landscape
  • Exceptional drought tolerance once established
  • Attracts native bees and butterflies
  • Requires virtually no maintenance

Where Does Silver’s Milkvetch Shine?

This native beauty is perfect for gardeners who want to create sustainable, water-wise landscapes. It’s an excellent choice for:

  • Xeriscapes and desert gardens
  • Native plant gardens
  • Rock gardens
  • Wildflower meadows
  • Slopes and areas with poor soil

Silver’s milkvetch works wonderfully as a groundcover or as part of a mixed native planting. Its silvery foliage provides a nice backdrop for showier wildflowers, while its purple blooms add subtle pops of color throughout the growing season.

Growing Silver’s Milkvetch Successfully

The good news is that Silver’s milkvetch is remarkably easy to grow – as long as you remember it’s a desert native that prefers to be left alone!

Ideal Growing Conditions

  • Sunlight: Full sun (6+ hours of direct sunlight daily)
  • Soil: Well-draining sandy or rocky soil; avoid heavy clay
  • Water: Low water needs once established
  • Hardiness: Thrives in USDA zones 4-8

Planting and Care Tips

Spring is the ideal time to plant Silver’s milkvetch. Here’s how to give your new native the best start:

  • Plant in well-draining soil – this is non-negotiable for desert natives
  • Water regularly the first year to help establish roots
  • Once established, water only during extended dry periods
  • Avoid fertilizing – these plants are adapted to poor soils
  • Resist the urge to fuss – overwatering is the quickest way to kill this tough plant

Supporting Pollinators

One of the best reasons to grow Silver’s milkvetch is its value to native pollinators. The purple flower clusters are particularly attractive to native bees and butterflies. By planting this native species, you’re providing food for pollinators that co-evolved with these plants over thousands of years.

Is Silver’s Milkvetch Right for Your Garden?

Silver’s milkvetch is an excellent choice if you:

  • Live in the southwestern United States
  • Want to reduce water usage in your landscape
  • Appreciate subtle, natural beauty over flashy blooms
  • Want to support native wildlife
  • Prefer low-maintenance plants

However, it might not be the best fit if you prefer lush, high-water gardens or live in areas with heavy clay soil and high humidity.

The Bottom Line

Silver’s milkvetch proves that native plants don’t have to be boring. This hardy perennial offers drought tolerance, pollinator benefits, and subtle beauty – all with minimal care required. For gardeners in the Southwest looking to create sustainable, wildlife-friendly landscapes, Silver’s milkvetch deserves a spot in your native plant palette.

Remember, the best gardens work with nature rather than against it. By choosing natives like Silver’s milkvetch, you’re creating a landscape that’s not just beautiful, but also environmentally responsible and perfectly suited to your local climate.

Silver’s 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 subcinereus A. Gray - Silver's milkvetch

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