North America Native Plant

Monument Valley Milkvetch

Botanical name: Astragalus monumentalis var. monumentalis

USDA symbol: ASMOM6

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Monument Valley Milkvetch: A Rare Desert Gem for Native Plant Enthusiasts If you’re drawn to the rugged beauty of the American Southwest and want to bring a piece of that landscape home, Monument Valley milkvetch (Astragalus monumentalis var. monumentalis) might just be the perfect addition to your native plant collection. ...

Rare plant alert!

Region: Conservation status by state

Status: S4T2T3: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is imperiled: Extremely rare due to factor(s) making it especially vulnerable to extinction. Typically 6 to 20 occurrences or few remaining individuals (1,000 to 3,000) ⚘ 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. ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘

Monument Valley Milkvetch: A Rare Desert Gem for Native Plant Enthusiasts

If you’re drawn to the rugged beauty of the American Southwest and want to bring a piece of that landscape home, Monument Valley milkvetch (Astragalus monumentalis var. monumentalis) might just be the perfect addition to your native plant collection. This charming perennial legume is as rare as it is beautiful, making it a true treasure for dedicated native gardeners.

A Desert Native with Limited Range

Monument Valley milkvetch is native to the lower 48 states, but don’t let that broad description fool you – this plant has a very specific home. You’ll find it naturally growing in just two states: Arizona and Utah, where it thrives in the iconic landscapes of the Colorado Plateau region.

Why Consider This Rare Beauty?

Before we dive into the growing details, there’s something important you need to know: Monument Valley milkvetch has a Global Conservation Status of S4T2T3, which indicates it’s considered rare in the wild. This means if you’re interested in growing this plant, you’ll want to source it responsibly from reputable native plant nurseries that propagate their own stock rather than wild-collecting.

So why might you want to add this rare gem to your garden? Here are several compelling reasons:

  • Support native biodiversity by providing habitat for specialized pollinators
  • Create an authentic Southwest landscape that honors local ecology
  • Enjoy the delicate beauty of its purple to pink flowers
  • Participate in conservation efforts by growing rare native species

What Does It Look Like?

Monument Valley milkvetch displays the classic milkvetch charm with its compound leaves and clusters of small, pea-like flowers in shades of purple to pink. As a perennial, it returns year after year, gradually establishing itself as a permanent fixture in your desert garden.

Perfect Garden Settings

This isn’t a plant for every garden – and that’s perfectly fine! Monument Valley milkvetch shines in specific settings:

  • Desert and xeric gardens that celebrate arid landscapes
  • Native plant gardens focused on Southwest species
  • Rock gardens with excellent drainage
  • Naturalized areas that mimic high desert conditions

Growing Conditions and Care

Success with Monument Valley milkvetch comes down to recreating its natural habitat conditions. Think high desert: lots of sun, excellent drainage, and minimal water.

Essential growing requirements:

  • Full sun exposure
  • Well-drained, sandy or rocky soil
  • Low water needs once established
  • USDA hardiness zones 5-8

The most critical factor for success is drainage – these plants absolutely cannot tolerate wet feet. If your soil tends to hold moisture, consider creating raised beds or adding plenty of sand and gravel to improve drainage.

Planting and Establishment Tips

When planting Monument Valley milkvetch, patience is your friend. Like many desert natives, this plant may take some time to establish but will reward you with years of reliable performance once settled.

  • Plant in spring after the last frost
  • Water sparingly during the first year to encourage deep root development
  • Avoid fertilizers – these plants are adapted to nutrient-poor soils
  • Mulch lightly with gravel or decomposed granite rather than organic mulch

Supporting Pollinators

One of the best reasons to grow Monument Valley milkvetch is its value to native pollinators. The flowers provide nectar for various native bees and other pollinating insects that have co-evolved with Southwest flora. By growing this plant, you’re supporting these important ecological relationships.

A Word About Responsible Sourcing

Given its rare status, it’s crucial to obtain Monument Valley milkvetch from reputable sources that propagate their own plants rather than collecting from wild populations. Contact native plant societies in Arizona and Utah, or specialized native plant nurseries that focus on regional species. Your patience in finding responsibly sourced plants helps protect wild populations while still allowing you to enjoy this remarkable species.

Is This Plant Right for You?

Monument Valley milkvetch isn’t for every gardener or every garden, but if you’re passionate about native plants, particularly those from the Southwest, and you can provide the right growing conditions, this rare beauty could be a meaningful addition to your landscape. Just remember: with rarity comes responsibility. Choose your sources carefully, and take pride in participating in the conservation of this unique desert native.

Monument Valley 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 monumentalis Barneby - Monument Valley milkvetch

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