North America Native Plant

Douglas’ Spiny Milkvetch

Botanical name: Astragalus kentrophyta var. douglasii

USDA symbol: ASKED2

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Astragalus kentrophyta A. Gray ssp. douglasii (Barneby) W.A. Weber (ASKED4)   

Douglas’ Spiny Milkvetch: A Pacific Northwest Native Worth Knowing If you’re looking to add some authentic Pacific Northwest character to your garden, Douglas’ spiny milkvetch (Astragalus kentrophyta var. douglasii) might just be the native plant you didn’t know you needed. This perennial shrub brings a touch of wild western charm ...

Rare plant alert!

Region: Conservation status by state

Status: S5TX: Status is uncertain but is somewhere between the following rankings: Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Douglas’ Spiny Milkvetch: A Pacific Northwest Native Worth Knowing

If you’re looking to add some authentic Pacific Northwest character to your garden, Douglas’ spiny milkvetch (Astragalus kentrophyta var. douglasii) might just be the native plant you didn’t know you needed. This perennial shrub brings a touch of wild western charm to any landscape, though finding detailed growing information can be as elusive as spotting this plant in its natural habitat!

What is Douglas’ Spiny Milkvetch?

Douglas’ spiny milkvetch is a low-growing perennial shrub that stays compact and manageable in the garden. This native beauty typically grows under 1.5 feet tall and never exceeds 3 feet at maturity, making it perfect for gardeners who want native plants without the overwhelming size that some native species can reach.

You might also encounter this plant listed under its synonym Astragalus kentrophyta A. Gray ssp. douglasii, so don’t be confused if you see it referenced both ways in plant catalogs or botanical references.

Where Does It Call Home?

This variety of spiny milkvetch is native to the lower 48 states, specifically calling Oregon and Washington home. It’s a true Pacific Northwest native, adapted to the unique conditions of this bioregion.

Why Consider Douglas’ Spiny Milkvetch for Your Garden?

Here’s where things get a bit mysterious – and honestly, that’s part of this plant’s charm! While detailed cultivation information for this specific variety is limited, there are several compelling reasons to consider it:

  • True native status: Supporting local ecosystems by choosing plants that evolved in your region
  • Compact size: Perfect for smaller gardens or as part of larger native plantings
  • Perennial nature: Once established, it returns year after year
  • Low maintenance potential: Native plants are typically adapted to local conditions

The Growing Challenge

Here’s the honest truth about Douglas’ spiny milkvetch: specific growing information for this variety is surprisingly scarce. This could mean a few things – it might be quite rare in cultivation, it could be challenging to grow, or it simply hasn’t gained popularity among native plant enthusiasts yet.

What we do know is that it’s a perennial shrub adapted to Pacific Northwest conditions, which suggests it likely prefers:

  • Well-draining soil (most milkvetches dislike wet feet)
  • Full sun to partial shade
  • Moderate water once established
  • Cool, moist winters and drier summers typical of the region

A Word of Caution and Opportunity

The limited information available about this plant’s cultivation requirements and availability makes it something of a gardener’s wild card. If you’re interested in growing Douglas’ spiny milkvetch, you’ll likely need to:

  • Contact specialized native plant nurseries in the Pacific Northwest
  • Join local native plant societies for growing tips and potential sources
  • Be prepared for some trial and error in your growing approach
  • Consider it a gardening adventure rather than a guaranteed success

Is This Plant Right for You?

Douglas’ spiny milkvetch might be perfect for you if:

  • You’re passionate about growing true regional natives
  • You enjoy the challenge of growing lesser-known plants
  • You have experience with native plant cultivation
  • You’re willing to do some detective work to source and grow it

However, you might want to consider other options if you’re looking for a well-documented, easily available native plant with established growing guidelines.

The Bottom Line

Douglas’ spiny milkvetch represents both the excitement and challenge of native plant gardening. While we’d love to give you a complete growing guide, sometimes the most interesting native plants are also the most mysterious. If you decide to take on the challenge of growing this Pacific Northwest native, you’ll be joining a small but dedicated group of gardeners helping to preserve regional plant diversity – and you might just discover some growing secrets along the way!

Remember, every expert native gardener started somewhere, and sometimes the plants that teach us the most are the ones that don’t come with a manual.

Douglas’ Spiny 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 kentrophyta A. Gray - spiny milkvetch

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