Selby’s Rockcress: A Hardy Native Ground Cover for Western Gardens
If you’re looking for a tough, low-maintenance ground cover that can handle the harsh conditions of the American West, let me introduce you to Selby’s rockcress (Arabis selbyi). This unassuming little perennial might not win any flashy flower contests, but it’s exactly the kind of reliable, native performer that every western gardener should know about.
What is Selby’s Rockcress?
Selby’s rockcress is a native perennial that belongs to the mustard family. You might also see it listed under its synonym Boechera selbyi in some plant databases – botanists love to shuffle names around! This hardy little plant forms low, spreading mats that hug the ground, making it perfect for areas where you need reliable coverage without a lot of fuss.
Where Does It Call Home?
This tough cookie is native to the western United States, specifically calling Colorado, Nevada, New Mexico, Utah, and Wyoming home. In the wild, you’ll find it thriving in high-elevation areas where many other plants throw in the towel. It’s adapted to some pretty challenging conditions, which is great news for gardeners dealing with difficult spots in their landscapes.
Why You’ll Want This Plant in Your Garden
Here’s what makes Selby’s rockcress such a winner for western gardeners:
- Drought tolerance: Once established, this plant laughs in the face of dry spells
- Low maintenance: Perfect for busy gardeners who want beauty without the babying
- Native benefits: Supports local ecosystems and wildlife
- Early blooms: Provides nectar for pollinators when few other flowers are available
- Ground coverage: Excellent for preventing erosion on slopes or filling in rocky areas
Garden Design and Landscape Uses
Selby’s rockcress isn’t going to be the star of your perennial border, but it excels as a supporting player. It’s absolutely perfect for:
- Rock gardens where it can cascade over stones
- Alpine gardens that mimic high-elevation environments
- Native plant gardens celebrating regional flora
- Xeriscaping projects focused on water conservation
- Difficult slopes that need erosion control
The plant forms low, spreading mats that work beautifully as living mulch around larger native shrubs or as filler between stepping stones.
What to Expect: Size and Appearance
Don’t expect towering heights from this ground-hugger. Selby’s rockcress typically stays quite low, forming dense mats that spread slowly but surely. In spring, it produces clusters of small, four-petaled white flowers that may be modest in size but are cheerfully abundant. The blooms appear early in the season, providing crucial nectar for emerging pollinators when pickings are slim.
Growing Conditions and Care
The beauty of Selby’s rockcress lies in its simplicity. This plant thrives in conditions that would stress out more finicky species:
- Soil: Well-draining, sandy, or rocky soil – heavy clay is its enemy
- Light: Full sun to partial shade, though it performs best with good light
- Water: Low to moderate water needs; drought tolerant once established
- Climate: Hardy in USDA zones 4-7, perfect for mountain and high-desert regions
Planting and Establishment Tips
Getting Selby’s rockcress established is refreshingly straightforward:
- Plant in spring or fall when temperatures are moderate
- Ensure excellent drainage – this is non-negotiable for success
- Space plants according to how quickly you want coverage
- Water regularly the first season, then back off significantly
- Resist the urge to fertilize – this plant prefers lean conditions
The biggest mistake gardeners make with rockcress species is overwatering. Once established, less is definitely more when it comes to irrigation.
Supporting Wildlife and Pollinators
While Selby’s rockcress might look unassuming, it pulls its weight in supporting local wildlife. The early spring flowers provide nectar for small native bees and butterflies emerging from winter. Because it blooms when few other options are available, it can be crucial for pollinator survival during those lean early weeks of spring.
Is Selby’s Rockcress Right for Your Garden?
This plant is ideal if you:
- Garden in the western United States within its native range
- Have challenging, dry sites that need ground cover
- Want to support native ecosystems and wildlife
- Prefer low-maintenance, drought-tolerant plants
- Need erosion control on slopes or banks
However, it might not be the best choice if you’re looking for showy flowers, need quick coverage, or garden in areas with heavy, poorly-drained soils.
Selby’s rockcress represents the best of native western plants: tough, reliable, and perfectly adapted to challenging conditions. While it may not be the showiest plant in your garden, it’s the kind of steady performer that forms the backbone of successful native landscapes. Give it the well-draining conditions it craves, and it’ll reward you with years of low-maintenance ground coverage and early spring blooms that local pollinators will thank you for.
