North America Native Plant

Big Western Bittercress

Botanical name: Cardamine occidentalis

USDA symbol: CAOC

Life cycle: perennial

Habit: forb

Native status: Native to Alaska âš˜ Native to Canada âš˜ Native to the lower 48 states  

Synonyms: Cardamine pratensis L. var. occidentalis S. Watson ex B.L. Rob. (CAPRO)   

Big Western Bittercress: A Charming Native Groundcover for Cool Climate Gardens Looking for a delicate native wildflower that won’t fuss over your gardening skills? Meet big western bittercress (Cardamine occidentalis), a perennial gem that brings subtle beauty and ecological value to gardens across the Pacific Northwest and beyond. Don’t let ...

Big Western Bittercress: A Charming Native Groundcover for Cool Climate Gardens

Looking for a delicate native wildflower that won’t fuss over your gardening skills? Meet big western bittercress (Cardamine occidentalis), a perennial gem that brings subtle beauty and ecological value to gardens across the Pacific Northwest and beyond. Don’t let the name fool you – while it’s called big, this charming plant maintains a modest presence that works beautifully as a naturalistic groundcover.

What Makes Big Western Bittercress Special?

This native North American wildflower belongs to the mustard family and offers a perfect example of understated garden elegance. In spring, clusters of small white to pale pink four-petaled flowers dance above compound leaves with distinctive rounded leaflets. The blooms may be delicate, but they pack a punch when it comes to supporting early-season pollinators who are desperately seeking nectar after a long winter.

As a perennial forb (that’s garden-speak for a non-woody flowering plant), big western bittercress returns year after year, gradually forming lovely colonies through self-seeding. It’s the kind of plant that makes you look like a gardening genius without requiring advanced degrees in horticulture.

Where Does It Call Home?

Big western bittercress is proudly native to western North America, naturally occurring from Alaska down through British Columbia, Washington, Oregon, and into California. This impressive native range means it’s perfectly adapted to the cool, moist conditions that characterize much of the Pacific Coast and mountain regions.

Perfect Growing Conditions

This adaptable native thrives in USDA hardiness zones 3-8, making it suitable for a wide range of climates. Here’s what big western bittercress loves most:

  • Moist to wet soils (it’s classified as a facultative wetland plant)
  • Partial shade to full sun exposure
  • Cool, temperate climates
  • Rich, organic soil that doesn’t dry out completely

The plant’s wetland status means it’s particularly happy near streams, in rain gardens, or anywhere that stays consistently moist. However, its facultative designation means it can also tolerate drier conditions once established, though it won’t be quite as robust.

Garden Design and Landscape Uses

Big western bittercress shines in several garden settings:

  • Woodland gardens: Perfect for naturalizing under trees where it mimics its forest floor habitat
  • Rain gardens: Excellent choice for managing water runoff while adding beauty
  • Native plant gardens: Essential for authentic regional plant communities
  • Naturalized landscapes: Creates effortless-looking drifts that support local ecosystems
  • Groundcover applications: Forms attractive colonies without being aggressive

Wildlife and Pollinator Benefits

Don’t underestimate this modest wildflower’s ecological importance! Big western bittercress serves as an early-season lifeline for pollinators emerging from winter dormancy. Small butterflies, native bees, and other beneficial insects rely on its nectar when few other flowers are available. The plant also provides habitat and food sources for various wildlife throughout the growing season.

Planting and Care Tips

Good news for busy gardeners – big western bittercress is refreshingly low-maintenance once established. Here’s how to succeed:

  • Starting from seed: Direct sow in fall or early spring, or cold-stratify seeds for 4-6 weeks before sowing
  • Planting: Choose a location with consistent moisture and morning sun or bright shade
  • Watering: Keep soil evenly moist, especially during establishment
  • Maintenance: Minimal care needed – just remove dead flower heads if you want to prevent self-seeding
  • Propagation: Allow natural self-seeding for expanding colonies, or collect seeds in summer

Why Choose Big Western Bittercress?

This native wildflower offers the perfect combination of beauty, ecological value, and easy care that every gardener dreams of. It’s particularly valuable for gardeners in the Pacific Northwest and mountain regions who want to create authentic native plant communities that support local wildlife.

Whether you’re developing a woodland garden, establishing a rain garden, or simply want to add some native charm to your landscape, big western bittercress delivers lasting beauty with minimal effort. Plus, you’ll have the satisfaction of knowing you’re supporting native pollinators and contributing to local ecosystem health – not bad for such an unassuming little plant!

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Alaska

FACW

Facultative Wetland - Plants with this status usually occurs in wetlands but may occur in non-wetlands

Arid West

FACW

Facultative Wetland - Plants with this status usually occurs in wetlands but may occur in non-wetlands

Western Mountains, Valleys, and Coast

FACW

Facultative Wetland - Plants with this status usually occurs in wetlands but may occur in non-wetlands

Big Western Bittercress

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Dilleniidae

Order

Capparales

Family

Brassicaceae Burnett - Mustard family

Genus

Cardamine L. - bittercress

Species

Cardamine occidentalis (S. Watson ex B.L. Rob.) Howell - big western bittercress

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