North America Native Plant

Wilson’s Milkvetch

Botanical name: Astragalus lentiginosus var. wilsonii

USDA symbol: ASLEW

Life cycle: biennial

Habit: forb

Native status: Native to the lower 48 states  

Wilson’s Milkvetch: A Rare Arizona Native Worth Knowing If you’re passionate about native plants and happen to garden in Arizona, you might want to get acquainted with Wilson’s milkvetch (Astragalus lentiginosus var. wilsonii). This lesser-known native biennial deserves a spot on your radar, even if it’s not quite ready for ...

Wilson’s Milkvetch: A Rare Arizona Native Worth Knowing

If you’re passionate about native plants and happen to garden in Arizona, you might want to get acquainted with Wilson’s milkvetch (Astragalus lentiginosus var. wilsonii). This lesser-known native biennial deserves a spot on your radar, even if it’s not quite ready for prime time in most garden centers.

What Makes Wilson’s Milkvetch Special?

Wilson’s milkvetch is a biennial plant, meaning it completes its life cycle over two years. In its first year, it focuses on establishing roots and foliage, then flowers and produces seeds in its second year before completing its cycle. This patient approach to life makes it an interesting addition to gardens designed around natural plant rhythms.

As a native species to the lower 48 states, Wilson’s milkvetch has evolved specifically to thrive in North American conditions. This Arizona native represents the kind of specialized regional flora that makes local ecosystems so fascinating and unique.

Where Does It Grow?

Wilson’s milkvetch calls Arizona home, where it has adapted to the state’s distinctive climate and soil conditions. This geographic specificity means it’s perfectly suited to Arizona gardens and landscapes, though it may be challenging to find in cultivation.

Should You Grow Wilson’s Milkvetch?

Here’s where things get a bit tricky – and honestly, pretty exciting for the adventurous native plant enthusiast. Wilson’s milkvetch is one of those plants that hasn’t made its way into mainstream horticulture yet. While we know it’s a native Arizona biennial, specific information about its growing requirements, appearance, and garden performance remains limited.

This presents both a challenge and an opportunity:

  • The Challenge: You won’t find detailed growing guides or readily available plants at your local nursery
  • The Opportunity: You could be among the first gardeners to experiment with this native species

What We Know (And What We Don’t)

While specific details about Wilson’s milkvetch are scarce, we can make some educated assumptions based on its native status and biennial nature. As an Arizona native, it likely prefers:

  • Well-draining soils
  • Low to moderate water requirements once established
  • Full sun to partial shade conditions typical of its natural habitat

However, we’d love to know more about its specific growing conditions, pollinator relationships, wildlife benefits, and aesthetic qualities. This is where the native plant community could really benefit from more research and cultivation trials.

The Bottom Line

Wilson’s milkvetch represents the fascinating world of lesser-known native plants that could potentially enrich our gardens and support local ecosystems. While we can’t provide a complete growing guide just yet, Arizona gardeners interested in pushing the boundaries of native plant gardening might want to keep this species on their wish list.

If you’re curious about Wilson’s milkvetch, consider reaching out to local native plant societies, botanical gardens, or university extension programs. They might have more specific information or even be interested in collaborative cultivation efforts. Sometimes the most rewarding gardening adventures begin with the plants we know least about!

Wilson’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 lentiginosus Douglas ex Hook. - freckled milkvetch

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