North America Native Plant

Smooth Aster

Botanical name: Eucephalus glabratus

USDA symbol: EUGL18

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Aster brickellioides Greene var. glabratus (ASBRG)  âš˜  Aster siskiyouensis A. Nelson & J.F. Macbr. (ASSI8)   

Smooth Aster: A Late-Season Native Gem for Your Garden If you’re looking for a native wildflower that brings life to your garden when many other plants are calling it quits for the season, meet the smooth aster (Eucephalus glabratus). This charming perennial might not be the showiest plant in your ...

Rare plant alert!

Region: Conservation status by state

Status: S3?: Status is uncertain but is somewhere between the following rankings: Inexact rank: ⚘ 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 ⚘

Smooth Aster: A Late-Season Native Gem for Your Garden

If you’re looking for a native wildflower that brings life to your garden when many other plants are calling it quits for the season, meet the smooth aster (Eucephalus glabratus). This charming perennial might not be the showiest plant in your garden, but it’s definitely one of the most reliable when it comes to providing late-season color and pollinator support.

What Makes Smooth Aster Special

Smooth aster is a true Pacific Northwest native, naturally found in the mountainous regions of California and Oregon. As a member of the aster family, it produces those classic daisy-like flowers we all love – small, delicate blooms in white to pale purple that appear when most summer flowers are fading away.

This perennial forb (that’s garden-speak for a non-woody flowering plant) grows as a low-maintenance herbaceous plant that dies back to the ground each winter and returns reliably each spring.

Why Your Garden Needs This Native Beauty

Here’s where smooth aster really shines – it’s like having a late-season buffet for pollinators right in your backyard. When butterflies, bees, and other beneficial insects are scrambling to find nectar sources in late summer and fall, your smooth aster will be there delivering the goods.

Beyond its pollinator benefits, this native plant offers several advantages:

  • Low water requirements once established
  • Thrives in well-drained soils
  • Adds natural texture to wildflower gardens
  • Perfect for naturalistic landscape designs
  • Extremely low maintenance

Where to Plant Smooth Aster

Smooth aster is particularly well-suited for:

  • Native plant gardens
  • Rock gardens and alpine settings
  • Naturalized meadow areas
  • Drought-tolerant landscape designs
  • Wildlife habitat gardens

Growing Conditions and Care

The beauty of smooth aster lies in its simplicity. This native thrives in USDA hardiness zones 5-8 and asks for very little once you get it established.

Light: Full sun to partial shade (though it performs best with at least 6 hours of direct sunlight)

Soil: Well-drained soils are absolutely essential – this plant cannot tolerate soggy feet. It’s quite adaptable to different soil types as long as drainage is good.

Water: Drought tolerant once established, but appreciates occasional deep watering during extended dry spells

Maintenance: Minimal! Simply cut back the dead growth in late fall or early spring.

A Word About Conservation

Here’s something important to know: smooth aster has a conservation status that suggests it may be somewhat uncommon in parts of its range. If you’re interested in adding this native beauty to your garden, make sure you source your plants or seeds from reputable native plant nurseries that use responsibly collected material. Never collect plants from the wild!

Getting Started with Smooth Aster

The best time to plant smooth aster is in fall or early spring. Give each plant plenty of space – while specific size information varies, most asters in this family appreciate room to spread naturally.

If you’re starting from seed, fall sowing often works well for native plants like this one, as they often need a period of cold stratification to germinate properly.

The Bottom Line

Smooth aster might not be the flashiest plant in the native plant world, but it’s exactly the kind of reliable, low-maintenance native that forms the backbone of a successful wildlife garden. Its late-season blooms provide crucial support for pollinators when they need it most, and its minimal care requirements make it perfect for busy gardeners who want to support local ecosystems without a lot of fuss.

If you’re in California or Oregon and looking to add more native plants to your landscape, smooth aster deserves a spot on your list. Just remember to source it responsibly, and you’ll have a beautiful, beneficial addition to your garden for years to come.

Smooth Aster

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

Eucephalus Nutt. - aster

Species

Eucephalus glabratus (Greene) Greene - smooth aster

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