Howell’s Pioneer Rockcress: A Specialized Western Native Worth Knowing
If you’re drawn to the world of specialized native plants, Howell’s pioneer rockcress (Arabis platysperma var. howellii) might just capture your imagination. This perennial forb represents one of those fascinating plants that quietly inhabits specific corners of the American West, though it’s definitely not your run-of-the-mill garden center find.
What Makes This Plant Special
Howell’s pioneer rockcress belongs to the mustard family and lives up to its pioneer name by growing in challenging, rocky environments. As a perennial herb, it lacks the woody stems you’d find on shrubs or trees, instead growing as a non-woody plant that returns year after year. This variety has quite the collection of historical names, having been known by botanists as Arabis covillei, Arabis conferta, Arabis howellii, and several other scientific names over the years.
Where You’ll Find It Growing Wild
This rockcress calls the western United States home, with native populations scattered across California, Idaho, Nevada, and Oregon. It’s a true western specialist, adapted to the unique growing conditions found in this region.
Should You Try Growing It?
Here’s where things get interesting – and a bit challenging. Howell’s pioneer rockcress isn’t exactly what you’d call a beginner-friendly garden plant. While it’s undeniably a legitimate native species with ecological value, very little information exists about its cultivation requirements, and it’s rarely (if ever) available through standard nursery channels.
The Reality Check
If you’re hoping to add this plant to your garden, you’ll need to manage your expectations. Here’s what we know and don’t know:
- It’s a perennial, so it should return each year if properly established
- True to its rockcress name, it likely prefers rocky, well-draining conditions
- Specific growing requirements, hardiness zones, and care instructions aren’t well documented
- Seeds or plants aren’t readily available commercially
- Its natural rarity status and specific habitat needs are unclear
Better Alternatives for Most Gardeners
Unless you’re a dedicated native plant specialist with access to ethically sourced material, you might consider these more readily available western native alternatives:
- Other Arabis species that are better documented and available
- Native penstemon varieties for rocky gardens
- Regional wildflowers suited to your specific location
If You’re Determined to Try
Should you somehow locate seeds or plants of Howell’s pioneer rockcress, approach with caution and respect:
- Only work with responsibly sourced, legally obtained material
- Never collect from wild populations
- Expect it to need rocky, well-draining soil based on its common name
- Be prepared for potential challenges and failures
- Consider it an experimental addition rather than a reliable garden staple
The Bottom Line
Howell’s pioneer rockcress represents one of those intriguing native plants that reminds us how much we still don’t know about our regional flora. While it’s certainly a legitimate part of western ecosystems, it’s probably not the best choice for most home gardeners. If you’re passionate about growing challenging native species and have access to proper material, it might be worth a try – just don’t expect it to behave like your typical garden perennial.
Sometimes the most interesting plants are the ones that remain just slightly out of reach, continuing their quiet existence in their chosen wild habitats while we admire them from afar.
