Macoun’s Rockcress: A Hardy Native Gem for Rock Gardens
If you’re looking for a tough, low-maintenance native plant that thrives in challenging conditions, meet Macoun’s rockcress (Arabis microphylla var. macounii). This unassuming little perennial might not win any beauty contests, but it’s got character in spades and deserves a spot in the right garden.
What is Macoun’s Rockcress?
Macoun’s rockcress is a native North American perennial herb that belongs to the mustard family. As a forb, it’s a non-woody plant that stays relatively low to the ground, making it perfect for tucking into rock crevices and alpine settings. You might also see it listed under its synonyms Arabis macounii or Boechera microphylla var. macounii in older gardening references.
Where Does It Grow Naturally?
This hardy native calls the mountainous regions of western North America home. You’ll find Macoun’s rockcress growing wild in British Columbia, Idaho, Montana, Utah, and Wyoming, where it has adapted to some pretty tough conditions. It’s native to both Canada and the lower 48 states, making it a true North American original.
Why Grow Macoun’s Rockcress?
Here’s where this little plant really shines. Macoun’s rockcress is the perfect choice for gardeners who want to:
- Create authentic native plant gardens using regional species
- Add texture and interest to rock gardens and alpine settings
- Establish low-maintenance ground cover in challenging spots
- Support local pollinators with spring blooms
- Garden sustainably with drought-tolerant plants
The plant produces clusters of small white flowers in spring that may look modest, but they’re valuable nectar sources for native bees, flies, and other small pollinators. Its silvery-green foliage forms attractive low mats that provide year-round structure in the garden.
Perfect Garden Settings
Macoun’s rockcress isn’t meant for every garden, and that’s perfectly fine. This specialized beauty thrives in:
- Rock gardens and alpine gardens
- Xeriscaping and drought-tolerant landscapes
- Native plant gardens focused on regional flora
- Naturalistic landscapes that mimic local ecosystems
- Slope stabilization projects in suitable climates
Growing Conditions and Care
The secret to success with Macoun’s rockcress is thinking like a mountain plant. This tough little perennial is hardy in USDA zones 3-7 and prefers:
- Soil: Well-draining, gravelly or sandy soil (drainage is crucial!)
- Light: Full sun to partial shade
- Water: Drought tolerant once established; avoid overwatering
- pH: Adaptable to various pH levels
Planting and Care Tips
Getting Macoun’s rockcress established is straightforward if you remember its mountain origins:
- Plant in spring or early fall when temperatures are moderate
- Ensure excellent drainage – this plant hates wet feet
- Add gravel or coarse sand to heavy soils to improve drainage
- Water regularly the first season, then reduce significantly
- Minimal fertilization needed – these plants prefer lean soils
- Deadhead spent flowers if desired, though it’s not necessary
Once established, Macoun’s rockcress is remarkably low-maintenance. It’s adapted to survive with minimal water and poor soils, making it an excellent choice for water-wise gardening.
Is It Right for Your Garden?
Macoun’s rockcress is definitely a specialty plant rather than a mainstream garden choice. It’s perfect if you’re creating a native plant garden focused on western North American species, developing a rock garden, or working with challenging, dry conditions. However, if you’re looking for showy flowers or lush foliage, you might want to consider other native options.
The biggest consideration is drainage – this plant simply won’t survive in heavy, moisture-retentive soils. But give it the right conditions, and you’ll have a tough, long-lived native that requires almost no care once established.
For gardeners in its native range who want to create authentic, sustainable landscapes that support local ecosystems, Macoun’s rockcress is a wonderful choice that honors the natural heritage of western North American mountains.
