North America Native Plant

Patterson’s Milkvetch

Botanical name: Astragalus pattersonii

USDA symbol: ASPA14

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Patterson’s Milkvetch: A Tough-as-Nails Native for Southwest Gardens If you’re looking for a low-maintenance, drought-tolerant native plant that won’t take over your garden, Patterson’s milkvetch (Astragalus pattersonii) might just be your new best friend. This unassuming little shrub packs a lot of personality into its compact frame, making it a ...

Patterson’s Milkvetch: A Tough-as-Nails Native for Southwest Gardens

If you’re looking for a low-maintenance, drought-tolerant native plant that won’t take over your garden, Patterson’s milkvetch (Astragalus pattersonii) might just be your new best friend. This unassuming little shrub packs a lot of personality into its compact frame, making it a perfect choice for gardeners who want beauty without the fuss.

What Exactly Is Patterson’s Milkvetch?

Patterson’s milkvetch is a perennial native plant that calls the American Southwest home. Don’t let the name fool you – while it’s called a milkvetch, it’s actually a member of the pea family and produces lovely small flowers that look just like tiny sweet peas. This hardy little plant stays refreshingly small, typically growing under 1.5 feet tall and never exceeding 3 feet, making it perfect for gardeners who prefer plants that know their place.

Where You’ll Find It Growing Wild

This resilient native grows naturally across four southwestern states: Arizona, Colorado, New Mexico, and Utah. It’s perfectly adapted to the challenging conditions of the American Southwest, which is exactly why it makes such a fantastic garden plant in these regions.

Why Your Garden (and Local Wildlife) Will Love It

Patterson’s milkvetch brings several wonderful qualities to your landscape:

  • Beautiful purple to violet pea-like flowers that bloom in spring
  • Attractive silvery-green compound leaves that add textural interest
  • Compact, shrubby form that works well as a groundcover or accent plant
  • Flowers that attract native bees and other beneficial pollinators
  • Incredible drought tolerance once established

Perfect Garden Situations

This adaptable native shines in several garden styles:

  • Xeriscape and drought-tolerant gardens
  • Rock gardens and alpine plantings
  • Native plant gardens
  • Desert and southwestern-style landscapes
  • Low-water groundcover applications

Growing Conditions That Make It Happy

Patterson’s milkvetch is refreshingly easy to please. It thrives in USDA hardiness zones 4-8, making it suitable for a wide range of climates. Here’s what it needs to flourish:

  • Full sun exposure
  • Well-draining soils (this is crucial!)
  • Poor to moderate soil fertility – it actually prefers lean conditions
  • Minimal water once established
  • Good air circulation

Planting and Care Tips for Success

Getting Patterson’s milkvetch established is straightforward if you follow a few simple guidelines:

When to plant: Fall or early spring are your best bets for planting success.

Watering wisdom: Water regularly during the first growing season to help establish roots, then back off significantly. Once established, this plant is incredibly drought tolerant and actually prefers to stay on the dry side. Overwatering is probably the quickest way to kill it.

Soil prep: If your soil tends to hold water, consider amending with sand or gravel to improve drainage. This plant would much rather deal with poor, rocky soil than rich, moisture-retentive earth.

Maintenance: Practically none! This is a plant it and forget it kind of native. You might want to deadhead spent flowers if you’re feeling ambitious, but it’s not necessary.

The Bottom Line

Patterson’s milkvetch is an excellent choice for southwestern gardeners who want to support native wildlife while creating a beautiful, low-maintenance landscape. Its combination of attractive flowers, interesting foliage, compact size, and bulletproof drought tolerance make it a winner for native plant gardens, rock gardens, and xeriscape designs. Just remember the golden rule: when in doubt, water less rather than more. This tough little native will reward your restraint with years of reliable beauty.

Patterson’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 pattersonii A. Gray ex Brandegee - Patterson'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