Howell’s Thelypody: A Rare Pacific Northwest Native Worth Protecting
If you’re passionate about growing native plants and contributing to conservation efforts, Howell’s thelypody (Thelypodium howellii) might just capture your heart—and your gardening conscience. This unassuming member of the mustard family represents one of those special plants that connects us directly to the wild heritage of the Pacific Northwest.
What Makes Howell’s Thelypody Special?
Howell’s thelypody is a native forb—essentially a soft-stemmed flowering plant without woody tissue—that calls California, Oregon, and Washington home. Unlike many garden-variety plants, this little beauty has earned itself a rather sobering distinction: it’s classified as imperiled, with a Global Conservation Status of S2. What does that mean for gardeners? There are likely only 6 to 20 known populations left in the wild, with somewhere between 1,000 to 3,000 individual plants total.
This rarity status makes Howell’s thelypody both a treasure and a responsibility. While it’s native to the lower 48 states and perfectly suited to Pacific Northwest gardens, growing it comes with the important caveat of sourcing plant material responsibly.
Garden Appeal and Design Role
As a biennial or perennial forb, Howell’s thelypody brings a delicate, naturalistic charm to garden spaces. During its blooming period in late spring to early summer, it produces clusters of small, pale flowers that range from white to soft purple—perfect for gardeners who appreciate subtle beauty over flashy displays.
This plant works wonderfully in:
- Native plant gardens focused on Pacific Northwest species
- Rock gardens and well-drained slope plantings
- Conservation-minded landscapes
- Naturalized meadow areas
Growing Conditions and Care
Like many Pacific Northwest natives, Howell’s thelypody has adapted to the region’s Mediterranean-style climate with wet winters and dry summers. It thrives in well-drained soils and can handle the specialized growing conditions that many garden plants simply can’t tolerate.
Key growing requirements include:
- Well-draining soil (it naturally grows in rocky areas and specialized soil types)
- Full sun to partial shade exposure
- USDA hardiness zones 8-10 (typical for its native range)
- Minimal summer water once established
Pollinator and Wildlife Benefits
When Howell’s thelypody blooms, it becomes a valuable resource for small pollinators, including native bees and butterflies. As part of the mustard family, its flowers provide both nectar and pollen, supporting the intricate web of relationships that keep Pacific Northwest ecosystems healthy.
The Conservation Consideration
Here’s where growing Howell’s thelypody gets interesting—and important. Because of its imperiled status, this isn’t a plant you can casually pick up at your local nursery. If you’re determined to grow this rare beauty, you’ll need to ensure your plant material comes from ethical, conservation-minded sources that don’t impact wild populations.
Consider reaching out to:
- Native plant societies in the Pacific Northwest
- Conservation organizations working with rare plants
- Specialty nurseries that propagate from ethically sourced seed
Should You Grow Howell’s Thelypody?
The answer depends on your gardening goals and commitment level. If you’re passionate about plant conservation and have the patience to source material responsibly, growing Howell’s thelypody can be a meaningful way to support the survival of this imperiled species. Every garden that successfully grows and potentially propagates this plant becomes a small conservation refuge.
However, if you’re looking for an easy-to-find Pacific Northwest native, there are many other wonderful options that don’t carry the same conservation concerns. The key is understanding that with Howell’s thelypody, you’re not just growing a plant—you’re participating in its preservation.
By choosing to grow responsibly sourced Howell’s thelypody, you’re joining a community of gardeners who understand that sometimes the most rewarding plants to grow are the ones that need us most.
