North America Native Plant

Willamette Fleabane

Botanical name: Erigeron decumbens var. robustior

USDA symbol: ERDER2

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Erigeron decumbens Nutt. ssp. robustior Cronquist (ERDER)   

Willamette Fleabane: A Charming Native Ground Cover for Pacific Coast Gardens Meet Willamette fleabane (Erigeron decumbens var. robustior), a delightful little native wildflower that’s been quietly carpeting parts of the Pacific Coast for centuries. Despite its somewhat unfortunate common name – fleabane doesn’t exactly roll off the tongue like sunflower ...

Rare plant alert!

Region: Conservation status by state

Status: S4T3: Status is uncertain but is somewhere between the following rankings: 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 ⚘

Willamette Fleabane: A Charming Native Ground Cover for Pacific Coast Gardens

Meet Willamette fleabane (Erigeron decumbens var. robustior), a delightful little native wildflower that’s been quietly carpeting parts of the Pacific Coast for centuries. Despite its somewhat unfortunate common name – fleabane doesn’t exactly roll off the tongue like sunflower – this unassuming perennial deserves a spot in your native plant wishlist.

Where Does Willamette Fleabane Call Home?

This charming forb is native to the lower 48 states, with its primary stomping grounds in California. True to its name, it has strong ties to Oregon’s Willamette Valley region, though you’ll find populations scattered throughout suitable habitats in the Pacific Northwest.

What Makes This Plant Special?

Willamette fleabane is a perennial forb, which simply means it’s a non-woody plant that comes back year after year. It grows as a low, mat-forming ground cover that produces clusters of small, daisy-like flowers. The blooms typically feature white to pale purple petals surrounding sunny yellow centers – classic wildflower charm that never goes out of style.

A Word About Rarity

Here’s something important to know: Willamette fleabane has a Global Conservation Status of S4T3, indicating it’s considered somewhat uncommon in its natural range. If you’re interested in growing this plant, please make sure you source it responsibly from reputable native plant nurseries rather than collecting from wild populations.

Why Grow Willamette Fleabane?

There are several compelling reasons to consider this native beauty for your garden:

  • It’s a pollinator magnet, attracting native bees, butterflies, and other beneficial insects
  • Once established, it’s quite drought-tolerant – perfect for water-wise gardening
  • Its low, spreading habit makes it excellent for rock gardens or as a naturalized ground cover
  • As a native species, it supports local ecosystems and wildlife
  • It requires minimal maintenance once settled in

Where to Plant It

Willamette fleabane thrives in USDA hardiness zones 7-9, making it suitable for much of the Pacific Coast and similar climates. It’s particularly well-suited for:

  • Native plant gardens
  • Rock gardens and alpine settings
  • Xeriscapes and drought-tolerant landscapes
  • Naturalized meadow areas
  • Slopes and areas where you need erosion control

Growing Conditions and Care

Like many California natives, Willamette fleabane isn’t particularly fussy once you understand its preferences:

Sunlight: Provide full sun to partial shade. It can handle some afternoon shade in hotter climates.

Soil: Well-draining soil is crucial. It’s adapted to rocky, sandy, or loamy soils but will struggle in heavy clay or waterlogged conditions.

Water: This is where many gardeners go wrong with native plants. Willamette fleabane prefers moderate water during establishment but should be kept on the dry side once mature. Overwatering is more likely to kill it than drought.

Planting and Care Tips

Getting Willamette fleabane established successfully is all about mimicking its natural habitat:

  • Plant in spring when soil temperatures are warming up
  • Amend heavy soils with sand or gravel to improve drainage
  • Water regularly during the first growing season, then reduce frequency
  • Avoid fertilizing – these plants are adapted to lean soils
  • Allow spent flowers to go to seed to support wildlife and potentially get natural reseeding
  • Cut back old growth in late winter if desired, but it’s not necessary

The Bottom Line

Willamette fleabane might not be the showiest plant in your garden, but it’s exactly the kind of quiet achiever that makes native plant gardening so rewarding. It asks for little, gives back to local pollinators and wildlife, and adds authentic regional character to your landscape. Just remember to source it responsibly and give it the well-draining conditions it craves.

If you’re building a native plant collection or looking for low-maintenance ground cover options, this little fleabane deserves serious consideration – unfortunate name and all!

Willamette Fleabane

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Erigeron L. - fleabane

Species

Erigeron decumbens Nutt. - Willamette fleabane

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