North America Native Plant

Smallflowered Milkvetch

Botanical name: Astragalus nuttallianus var. austrinus

USDA symbol: ASNUA

Life cycle: annual

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Astragalus austrinus (Small) E.D. Schulz (ASAU6)   

Smallflowered Milkvetch: A Charming Native Annual for Southwestern Gardens Meet the smallflowered milkvetch (Astragalus nuttallianus var. austrinus), a delightful little native annual that’s perfectly suited for gardeners looking to embrace the natural beauty of the American Southwest. This unassuming wildflower might not win any height contests, but what it lacks ...

Smallflowered Milkvetch: A Charming Native Annual for Southwestern Gardens

Meet the smallflowered milkvetch (Astragalus nuttallianus var. austrinus), a delightful little native annual that’s perfectly suited for gardeners looking to embrace the natural beauty of the American Southwest. This unassuming wildflower might not win any height contests, but what it lacks in stature, it more than makes up for in charm and ecological value.

What Makes Smallflowered Milkvetch Special?

This native beauty is authentically American, naturally occurring across six states in the lower 48: Arizona, California, Colorado, New Mexico, Oklahoma, and Texas. As a true native species, it’s perfectly adapted to the challenging conditions of southwestern landscapes, making it an excellent choice for gardeners who want to work with nature rather than against it.

You might also encounter this plant listed under its synonym, Astragalus austrinus, but don’t let the scientific names intimidate you – this is simply a case of botanists being, well, botanists!

Garden Appeal and Landscape Role

Smallflowered milkvetch brings a subtle, understated beauty to the garden with its delicate compound leaves and clusters of small white to pale yellow flowers. As an annual, it completes its entire life cycle in one growing season, making it perfect for:

  • Wildflower meadows and naturalized areas
  • Xeriscape gardens that celebrate drought-tolerant plants
  • Native plant collections
  • Ground cover in areas with poor or rocky soil

Perfect Growing Conditions

This southwestern native thrives in USDA hardiness zones 7-10, where it can take full advantage of the region’s abundant sunshine and well-draining soils. Here’s what makes smallflowered milkvetch happy:

  • Sunlight: Full sun exposure for best growth and flowering
  • Soil: Well-draining, sandy, or rocky soils – it actually prefers poor soils over rich ones
  • Water: Drought tolerant once established; minimal watering required
  • Climate: Thrives in arid and semi-arid conditions

Planting and Care Tips

Growing smallflowered milkvetch is refreshingly straightforward – this plant is built for survival in tough conditions. Here’s how to give it the best start:

  • Timing: Direct sow seeds in fall for spring germination
  • Soil preparation: No need for soil amendments – this plant actually prefers lean, poor soils
  • Watering: Water lightly during establishment, then let nature take over
  • Maintenance: Virtually maintenance-free once established

Wildlife and Pollinator Benefits

While smallflowered milkvetch may look modest, it plays an important role in supporting local ecosystems. The small flowers are perfectly sized for native bees and other small pollinators, providing them with valuable nectar and pollen resources. As part of the legume family, it also helps improve soil nitrogen content through its root nodules.

Should You Plant Smallflowered Milkvetch?

If you’re gardening in the Southwest and looking for authentic native plants that require minimal care while supporting local wildlife, smallflowered milkvetch deserves consideration. It’s particularly valuable for:

  • Gardeners embracing water-wise landscaping
  • Those wanting to support native pollinators
  • Anyone looking to create naturalized wildflower areas
  • Gardeners working with challenging, poor soils

While it may not be the showiest plant in your garden, smallflowered milkvetch offers something increasingly rare in our world: a plant that asks for very little while giving back to the ecosystem it calls home. In a world of high-maintenance garden plants, sometimes the most rewarding choice is the one that simply knows how to take care of itself.

Smallflowered 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 nuttallianus DC. - smallflowered milkvetch

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