North America Native Plant

Cascade Wallflower

Botanical name: Erysimum arenicola

USDA symbol: ERAR15

Life cycle: perennial

Habit: forb

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

Synonyms: Erysimum arenicola S. Watson var. arenicola (ERARA2)  âš˜  Erysimum arenicola S. Watson var. torulosum (Piper) C.L. Hitchc. (ERART)  âš˜  Erysimum torulosum Piper (ERTO4)   

Cascade Wallflower: A Pacific Northwest Native Worth Knowing If you’re looking for a cheerful, low-maintenance native plant that brings both color and ecological value to your Pacific Northwest garden, let me introduce you to the cascade wallflower (Erysimum arenicola). This delightful perennial might not be the most famous native on ...

Rare plant alert!

Region: Conservation status by state

Status: S4S5T3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ Subspecies or variety is vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals. ⚘ Apparently Secure: Uncommon but not rare, and usually widespread. Possibly cause for longterm concern. Typically more than 100 occurrences in the state or more than 10,000 individuals ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Cascade Wallflower: A Pacific Northwest Native Worth Knowing

If you’re looking for a cheerful, low-maintenance native plant that brings both color and ecological value to your Pacific Northwest garden, let me introduce you to the cascade wallflower (Erysimum arenicola). This delightful perennial might not be the most famous native on the block, but it’s definitely one worth getting to know – especially if you love plants that work hard without asking for much in return.

What Makes Cascade Wallflower Special?

Cascade wallflower is a true Pacific Northwest native, naturally occurring in British Columbia, Oregon, and Washington. As a member of the mustard family, this herbaceous perennial produces clusters of bright yellow to orange four-petaled flowers that bloom primarily in spring and early summer. The flowers sit atop sturdy stems above narrow, lance-shaped leaves, creating a compact and tidy appearance that gardeners absolutely love.

This native beauty grows naturally along the coastal regions of the Pacific Northwest, where it has adapted to sandy soils and variable moisture conditions. That coastal heritage makes it particularly valuable for gardeners dealing with challenging growing conditions.

Why You’ll Want Cascade Wallflower in Your Garden

Here’s where cascade wallflower really shines – it’s the perfect plant for gardeners who want maximum impact with minimal fuss. Once established, this native perennial is remarkably drought tolerant, making it an excellent choice for water-wise gardening. The bright, cheerful flowers provide a lovely pop of color in spring when many other plants are just waking up from winter.

But the benefits go beyond just looking pretty. Cascade wallflower is a pollinator magnet, attracting bees, butterflies, and other beneficial insects to your garden. By choosing this native plant, you’re supporting local ecosystems and providing food sources that native wildlife has evolved alongside for thousands of years.

Perfect Garden Roles

Cascade wallflower works beautifully in several garden settings:

  • Rock gardens: Its compact size and drought tolerance make it perfect for tucking between rocks
  • Coastal gardens: Naturally adapted to coastal conditions, it handles salt spray and sandy soils with ease
  • Native plant gardens: An authentic choice for Pacific Northwest native landscapes
  • Ground cover: Forms attractive low mounds that help suppress weeds
  • Border plants: Creates neat, colorful edges along pathways or garden beds

Growing Cascade Wallflower Successfully

The good news is that cascade wallflower is relatively easy to grow, especially if you can provide the right conditions from the start.

Ideal Growing Conditions

This native thrives in:

  • Sunlight: Full sun is best, though it can tolerate some light shade
  • Soil: Well-draining sandy or gravelly soils – heavy clay is not its friend
  • Water: Moderate water during establishment, then quite drought tolerant
  • Climate: Hardy in USDA zones 6-9, perfect for most Pacific Northwest gardens

Planting and Care Tips

Spring is the ideal time to plant cascade wallflower, giving it a full growing season to establish before winter. When planting, make sure your soil drains well – if water pools after rain, consider amending with sand or planting in a raised bed.

Water regularly during the first growing season to help establish a strong root system, but once established, you can cut back significantly on watering. In fact, overwatering is more likely to cause problems than underwatering with this drought-adapted native.

To keep your plants looking their best and encourage extended blooming, deadhead spent flowers regularly. This simple maintenance task can significantly extend the flowering period and keep your plants looking tidy.

A Note on Conservation

Cascade wallflower has a somewhat uncertain conservation status (listed as S4S5T3?), which essentially means more research is needed to fully understand its population stability. While this doesn’t mean it’s rare or endangered, it’s always wise to source your plants from reputable nurseries that propagate rather than wild-collect their stock.

The Bottom Line

If you’re gardening in the Pacific Northwest and looking for a reliable, beautiful native plant that supports local wildlife while requiring minimal care, cascade wallflower deserves serious consideration. It brings authentic regional character to your garden while supporting the pollinators and ecosystem that make our region so special.

Plus, there’s something deeply satisfying about growing a plant that truly belongs in your landscape – one that your local bees, butterflies, and other wildlife recognize as home.

Cascade Wallflower

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

Erysimum L. - wallflower

Species

Erysimum arenicola S. Watson - cascade wallflower

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