Native Plants

Gunnison’s Rockcress

Arabis gunnisoniana

USDA symbol: ARGU

perennial forb

Lower 48 states: native

If you’re passionate about native plants and love the challenge of growing something truly special, Gunnison’s rockcress (Arabis gunnisoniana) might just capture your heart. This delicate Colorado endemic is a hidden gem in the world of native gardening, though its rarity means you’ll need to approach it with extra care ...

Gunnison’s Rockcress may be listed as rare in your area.
Global Conservation Status

Status: S3 | Vulnerable: Found only in a restricted range (even if abundant at some locations). Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals.

Gunnison’s Rockcress: A Rare Colorado Native Worth Protecting in Your Garden

If you’re passionate about native plants and love the challenge of growing something truly special, Gunnison’s rockcress (Arabis gunnisoniana) might just capture your heart. This delicate Colorado endemic is a hidden gem in the world of native gardening, though its rarity means you’ll need to approach it with extra care and consideration.

What Makes Gunnison’s Rockcress Special?

Gunnison’s rockcress is a perennial forb that belongs to the mustard family. Don’t let the term forb intimidate you – it simply means it’s a non-woody flowering plant that comes back year after year. This charming little plant forms neat rosettes of leaves and produces clusters of small, four-petaled white flowers that brighten up the landscape in spring.

You might also see this plant listed under its scientific synonym, Boechera gunnisoniana, depending on which botanical reference you’re consulting. The plant world loves to keep us on our toes with name changes!

Where Does It Call Home?

Here’s where things get interesting – and important. Gunnison’s rockcress is found exclusively in Colorado, making it a true Colorado native. This isn’t just any run-of-the-mill native plant; it’s an endemic species that exists nowhere else on Earth.

  • Species observed
  • No observations

A Word of Caution: Rarity Matters

Before we dive into why you might want to grow this beauty, there’s something crucial you need to know. Gunnison’s rockcress has a Global Conservation Status of S3, which means it’s considered vulnerable. With typically only 21 to 100 occurrences and between 3,000 to 10,000 individuals in the wild, this plant needs our protection.

If you’re interested in growing Gunnison’s rockcress, please only obtain it from reputable native plant nurseries that grow it from ethically sourced seed or cuttings. Never collect it from the wild.

Why Grow Gunnison’s Rockcress?

Despite its rarity – or perhaps because of it – there are compelling reasons to consider this plant for your garden:

  • True Colorado native: Support local ecosystems and biodiversity
  • Pollinator magnet: Those spring flowers attract native bees and other beneficial insects
  • Low maintenance: Once established, it’s quite drought tolerant
  • Unique aesthetic: Adds authentic Colorado character to your landscape
  • Conservation impact: Growing it responsibly helps preserve the species

Perfect Garden Spots for This Rocky Mountain Native

Gunnison’s rockcress isn’t a plant for every garden situation, but it absolutely shines in the right spots:

  • Rock gardens: Its natural habitat inspiration makes it perfect here
  • Alpine gardens: Brings authentic high-country charm
  • Xeric landscapes: Thrives in low-water garden designs
  • Native plant gardens: A true conversation starter among fellow native plant enthusiasts

Growing Conditions: Keep It Rocky and Dry

Success with Gunnison’s rockcress comes down to mimicking its natural mountain habitat. Here’s what it craves:

  • Drainage is king: This plant absolutely must have well-draining soil
  • Sun to partial shade: Flexible with light conditions but needs some sun
  • USDA Zones 4-7: Hardy enough for most Colorado gardens and similar climates
  • Rocky or sandy soil: Think mountain scree rather than rich garden loam

Planting and Care Tips

Growing this rare beauty successfully requires attention to a few key details:

  • Soil prep: Amend heavy clay soils with coarse sand, gravel, or pumice to improve drainage
  • Watering: Water regularly the first year to establish roots, then cut back dramatically
  • Fertilizing: Skip the fertilizer – this plant prefers lean conditions
  • Mulching: Use gravel mulch instead of organic mulch to prevent crown rot
  • Winter care: No special protection needed in appropriate zones

The Bottom Line

Gunnison’s rockcress offers gardeners a chance to grow something truly special – a plant that exists nowhere else in the world. While its rarity means you need to source it responsibly and provide the right growing conditions, the reward is a unique piece of Colorado’s natural heritage in your own backyard.

If you’re up for the challenge and can provide excellent drainage and appropriate growing conditions, this little rockcress can be a meaningful addition to your native plant collection. Just remember: with great rarity comes great responsibility. Help protect this vulnerable species by growing it thoughtfully and sharing your knowledge with other gardeners.

Your garden could become a small sanctuary for one of Colorado’s special endemic plants – now that’s something worth growing!

Arabis gunnisoniana is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Arabis gunnisoniana is also known as:

Boechera gunnisoniana | USDA symbol: BOGU

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Dilleniidae
Order: Capparales
Family: Brassicaceae Burnett - Mustard family
Genus: Arabis L. - rockcress

Species: Arabis gunnisoniana Rollins - Gunnison's rockcress

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