North America Native Plant

Prostrate Mountain Phlox

Botanical name: Phlox austromontana prostrata

USDA symbol: PHAUP

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Phlox austromontana Coville var. prostrata E.E. Nelson (PHAUP2)   

Prostrate Mountain Phlox: A Low-Growing Native Gem for Southwestern Gardens If you’re looking for a low-maintenance, native ground cover that can handle the tough conditions of the American Southwest, prostrate mountain phlox (Phlox austromontana prostrata) might just be the plant you’ve been searching for. This lesser-known variety of mountain phlox ...

Prostrate Mountain Phlox: A Low-Growing Native Gem for Southwestern Gardens

If you’re looking for a low-maintenance, native ground cover that can handle the tough conditions of the American Southwest, prostrate mountain phlox (Phlox austromontana prostrata) might just be the plant you’ve been searching for. This lesser-known variety of mountain phlox brings native beauty to challenging landscapes where many other plants simply won’t thrive.

What Makes Prostrate Mountain Phlox Special?

Prostrate mountain phlox is a perennial forb herb that stays low to the ground, making it an excellent choice for gardeners who want native plant coverage without the height. As a true native of the southwestern United States, this plant has evolved to handle the unique challenges of desert and mountain environments that would stress out many non-native alternatives.

You might also see this plant listed under its botanical synonym, Phlox austromontana var. prostrata, but don’t let the scientific names intimidate you – this is simply a naturally occurring variety of mountain phlox that has adapted to grow in a spreading, low-lying form.

Where Does It Call Home?

This native beauty can be found naturally growing across four southwestern states: Arizona, California, Nevada, and Utah. Its natural range tells us a lot about what this plant can handle – think hot, dry summers and potentially cold mountain winters.

Why Choose Prostrate Mountain Phlox for Your Garden?

Here’s why this native ground cover deserves a spot in your southwestern landscape:

  • True native credentials: Unlike many popular ground covers, this plant actually belongs in southwestern ecosystems
  • Low-maintenance nature: Once established, native plants typically require far less water and care than non-natives
  • Unique prostrate form: The spreading, low-growing habit makes it perfect for areas where you want coverage without height
  • Drought tolerance: Based on its native range, this plant should handle dry conditions well once established

Garden Design Ideas

Prostrate mountain phlox works beautifully in several landscape settings:

  • Rock gardens: Its low profile complements boulders and rocky terrain perfectly
  • Native plant gardens: Combine it with other southwestern natives for an authentic regional look
  • Ground cover applications: Use it to fill in areas where grass struggles
  • Slope stabilization: The spreading habit may help prevent erosion on gentle slopes

Growing Conditions and Care

While specific growing requirements for this variety are not well-documented, we can make educated guesses based on its native habitat and related species:

  • Sunlight: Likely prefers full sun to partial shade
  • Soil: Probably thrives in well-draining, rocky, or sandy soils
  • Water: Once established, should be quite drought tolerant
  • Climate: Best suited for areas that experience the temperature ranges found in its native southwestern range

A Note on Availability

Here’s the honest truth: prostrate mountain phlox isn’t commonly found in typical garden centers. This native variety is somewhat of a specialty plant that you’ll likely need to source from native plant nurseries or specialized southwestern plant suppliers. If you can’t find it locally, consider reaching out to native plant societies in Arizona, California, Nevada, or Utah – they often have excellent resources for finding hard-to-locate native species.

The Bottom Line

Prostrate mountain phlox represents the kind of native plant that serious southwestern gardeners love to discover – tough, authentic, and perfectly adapted to regional conditions. While it may take some effort to track down, adding this low-growing native to your landscape connects your garden to the natural heritage of the American Southwest.

If you’re committed to using native plants and want something different from the usual suspects, prostrate mountain phlox could be exactly the unique ground cover your garden needs. Just be prepared to do a little detective work to find a source – but isn’t that half the fun of native plant gardening?

Prostrate Mountain Phlox

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Solanales

Family

Polemoniaceae Juss. - Phlox family

Genus

Phlox L. - phlox

Species

Phlox austromontana Coville - mountain phlox

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