North America Native Plant

Timber Milkvetch

Botanical name: Astragalus miser var. tenuifolius

USDA symbol: ASMIT

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Timber Milkvetch: A Hardy Western Native for Low-Maintenance Gardens If you’re looking for a tough-as-nails native perennial that can handle whatever Mother Nature throws its way, meet timber milkvetch (Astragalus miser var. tenuifolius). This unassuming little powerhouse might not win any beauty contests, but it’s got the kind of grit ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is 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. ⚘ 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. ⚘

Timber Milkvetch: A Hardy Western Native for Low-Maintenance Gardens

If you’re looking for a tough-as-nails native perennial that can handle whatever Mother Nature throws its way, meet timber milkvetch (Astragalus miser var. tenuifolius). This unassuming little powerhouse might not win any beauty contests, but it’s got the kind of grit and determination that makes it a gardener’s secret weapon in challenging landscapes.

Where Timber Milkvetch Calls Home

Timber milkvetch is a true child of the American West, naturally occurring across five states: Idaho, Montana, Nevada, Utah, and Wyoming. This native plant has spent countless generations adapting to the harsh conditions of the western landscape, making it perfectly suited for gardens in these regions.

What Does Timber Milkvetch Look Like?

Don’t expect flashy garden theater from this plant – timber milkvetch is more about quiet charm than showstopping drama. As a perennial, it comes back year after year, producing delicate purple to pink pea-like flowers arranged in small clusters. The compound leaves, made up of multiple small leaflets, give the plant a feathery, almost fern-like appearance that adds subtle texture to the garden.

Why Your Garden (and Local Wildlife) Will Love It

Here’s where timber milkvetch really shines: it’s a pollinator magnet. Native bees and other beneficial insects flock to its modest flowers for both nectar and pollen. In a world where pollinators need all the help they can get, planting native species like timber milkvetch is like rolling out the red carpet for these essential creatures.

The plant also fits beautifully into naturalized landscapes and native plant gardens, where its low-key presence helps create that authentic wild look without actually being wild and unruly.

Perfect Spots for Timber Milkvetch

This adaptable native works wonderfully in several garden styles:

  • Rock gardens where its drought tolerance shines
  • Xeriscapes and water-wise landscapes
  • Native plant gardens and prairie restorations
  • Naturalistic landscapes that mimic wild spaces

Growing Conditions That Make It Happy

Timber milkvetch thrives in USDA hardiness zones 4-8, making it suitable for much of the northern and western United States. Like many western natives, it prefers:

  • Full sun exposure
  • Well-drained soils (soggy feet are not its friend)
  • Minimal water once established
  • Poor to average soils – skip the rich, amended garden beds

Planting and Care Tips

The good news? Timber milkvetch is refreshingly low-maintenance once you understand its needs. Here’s how to set it up for success:

Getting Started: Direct seeding in fall works best, as the seeds need a period of cold stratification over winter. Spring planting is possible but may require pre-treating seeds.

Watering: Water moderately during establishment, then step back and let nature take over. This plant actually prefers lean conditions and can struggle with too much attention.

Soil Prep: Resist the urge to pamper with rich compost or fertilizers. Timber milkvetch evolved in tough conditions and performs best in average to poor soils with excellent drainage.

Maintenance: Minimal pruning needed – just remove any dead material in late winter or early spring.

Is Timber Milkvetch Right for Your Garden?

This native is perfect for gardeners who want to support local ecosystems while maintaining a beautiful, low-water landscape. It’s especially valuable if you’re gardening in its native range of Idaho, Montana, Nevada, Utah, or Wyoming, where it will feel completely at home.

However, if you’re looking for a high-impact ornamental with showy blooms, you might want to pair timber milkvetch with other natives that offer more visual punch. Think of it as a reliable supporting actor rather than the star of the show.

For western gardeners committed to native plants and sustainable landscaping, timber milkvetch offers the perfect combination of ecological benefits, low maintenance, and quiet beauty that makes a garden feel authentically connected to its place.

Timber 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 miser Douglas ex Hook. - timber milkvetch

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