North America Native Plant

Newberry’s Milkvetch

Botanical name: Astragalus newberryi var. castoreus

USDA symbol: ASNEC

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Newberry’s Milkvetch: A Lesser-Known Native Gem for Western Gardens If you’re looking to add some authentic western charm to your native garden, you might want to get acquainted with Newberry’s milkvetch (Astragalus newberryi var. castoreus). This perennial native plant represents the kind of under-the-radar gem that serious native plant enthusiasts ...

Newberry’s Milkvetch: A Lesser-Known Native Gem for Western Gardens

If you’re looking to add some authentic western charm to your native garden, you might want to get acquainted with Newberry’s milkvetch (Astragalus newberryi var. castoreus). This perennial native plant represents the kind of under-the-radar gem that serious native plant enthusiasts love to discover – though admittedly, it’s not going to win any popularity contests with mainstream gardeners anytime soon.

What is Newberry’s Milkvetch?

Newberry’s milkvetch is a perennial member of the legume family, native to six western states. Like its Astragalus cousins, this plant is part of a genus that includes hundreds of species, many of which have adapted to the challenging conditions of the American West. The scientific name Astragalus newberryi var. castoreus tells us this is a specific variety of Newberry’s milkvetch, named after the 19th-century botanist John Strong Newberry.

Where Does It Call Home?

This native plant has made itself at home across a impressive swath of the western United States. You’ll find Newberry’s milkvetch growing naturally in Arizona, California, Idaho, Nevada, Oregon, and Utah. This distribution suggests it’s adapted to a variety of western climates and conditions, from high desert to mountainous regions.

Why Consider Growing Newberry’s Milkvetch?

Here’s where things get interesting – and a bit challenging. While this plant’s native status makes it an appealing choice for authentic western gardens, specific information about this particular variety is surprisingly scarce. What we do know makes it worth considering:

  • True native credentials: Unlike many garden plants, this one actually belongs in western landscapes
  • Perennial staying power: Once established, it should return year after year
  • Potential pollinator support: As a legume, it likely provides nectar for native bees and other pollinators
  • Low-maintenance nature: Most Astragalus species are adapted to survive with minimal water and care

The Honest Truth About Growing It

Here’s where we need to have a frank conversation. Newberry’s milkvetch falls into that category of native plants that botanists know exist but gardeners rarely encounter. Information about its specific growing requirements, size, and garden performance is limited. This makes it more of an experimental addition than a sure bet for your landscape.

If you’re the adventurous type who enjoys trying uncommon natives, here’s what you can reasonably expect based on its Astragalus family traits:

  • Sun preference: Likely thrives in full sun conditions
  • Soil needs: Probably prefers well-draining soils and can handle poor, rocky conditions
  • Water requirements: Once established, likely drought-tolerant
  • Garden style: Best suited for naturalized areas and native plant collections rather than formal landscapes

The Bottom Line

Newberry’s milkvetch is one of those plants that appeals to native plant collectors and restoration enthusiasts more than typical home gardeners. If you can actually find it for sale (which might be the biggest challenge), it could be an interesting addition to a native plant garden or naturalized area.

However, if you’re looking for reliable native plants with more predictable garden performance, you might want to start with better-known western natives like penstemon, desert marigold, or other more commonly available Astragalus species. These will give you similar native plant benefits with much more gardening guidance available.

For the truly curious native plant enthusiast, Newberry’s milkvetch represents the kind of botanical treasure hunt that makes native gardening endlessly fascinating – even if the plant itself remains something of a mystery!

Newberry’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 newberryi A. Gray - Newberry'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