North America Native Plant

Thickstem Aster

Botanical name: Eurybia integrifolia

USDA symbol: EUIN9

Life cycle: perennial

Habit: subshrub

Native status: Native to the lower 48 states  

Synonyms: Aster integrifolius Nutt. (ASIN3)   

Thickstem Aster: A Hardy Native Wildflower for Western Gardens Looking for a tough-as-nails native wildflower that laughs in the face of drought? Meet the thickstem aster (Eurybia integrifolia), a delightfully resilient perennial that’s been quietly beautifying the American West long before any of us picked up a garden spade. This ...

Thickstem Aster: A Hardy Native Wildflower for Western Gardens

Looking for a tough-as-nails native wildflower that laughs in the face of drought? Meet the thickstem aster (Eurybia integrifolia), a delightfully resilient perennial that’s been quietly beautifying the American West long before any of us picked up a garden spade. This unassuming purple beauty might just be the low-maintenance garden hero you’ve been searching for.

What Makes Thickstem Aster Special?

Don’t let the thickstem name fool you into thinking this plant is chunky or ungainly. This herbaceous perennial grows into an elegant, upright form reaching about 3 feet tall. During late summer, it produces clusters of cheerful purple flowers that seem to glow against its coarse-textured green foliage. The blooms might not be the showiest in your garden, but they have a charming, wild beauty that screams I belong here!

As a true native of the western United States, thickstem aster has earned its stripes in some pretty tough neighborhoods. You’ll find this hardy survivor thriving naturally across California, Idaho, Montana, Nevada, Oregon, Utah, Washington, and Wyoming.

Why Your Garden (and Local Wildlife) Will Love It

Here’s where thickstem aster really shines as a garden companion:

  • Drought Champion: With high drought tolerance and low moisture needs, this plant practically thrives on neglect
  • Pollinator Magnet: Those purple late-summer blooms are like a last call buffet for bees, butterflies, and other beneficial insects
  • Fire Resistant: In fire-prone areas, this plant offers good fire tolerance
  • Fast Growing: Rapid growth rate means you won’t wait years to see results
  • Prolific Seeder: Produces abundant seeds that spread easily for natural expansion

Perfect Garden Situations

Thickstem aster isn’t trying to compete with your prize roses or perfectly manicured perennial borders. Instead, it excels in more relaxed, naturalistic settings:

  • Xeriscapes and drought-tolerant landscapes
  • Native plant gardens
  • Meadow and prairie-style plantings
  • Wildlife gardens focused on supporting pollinators
  • Naturalized areas where you want that wild look

Growing Conditions: Keep It Simple

One of the best things about thickstem aster is how uncomplicated its needs are. This plant has adapted to some pretty harsh conditions in the wild, which translates to easy gardening for you.

Soil: Prefers coarse to medium-textured, well-draining soils. It’s not picky about fertility—in fact, it prefers low-fertility conditions. Avoid heavy clay soils, as good drainage is crucial.

Sun: Full sun is essential. This sun-worshipper is shade intolerant, so don’t try to tuck it under trees or in shadowy corners.

Water: Once established, minimal watering needed. It can handle annual precipitation ranging from just 10 to 60 inches.

pH: Tolerates slightly acidic to neutral soils (pH 6.0-7.5) and has high tolerance for alkaline conditions.

Planting and Care Tips

Growing thickstem aster is refreshingly straightforward:

Starting from Seed: This is your best bet, as the plant isn’t commonly available commercially. With 880,000 seeds per pound and high seedling vigor, direct seeding in fall or early spring works well. Seeds spread rapidly on their own too, so expect natural expansion.

Spacing: Give plants room to spread—they have a moderate vegetative spread rate and multiple-stem growth form.

USDA Hardiness: Suitable for zones 5-9, tolerating temperatures down to -23°F.

Maintenance: Here’s the beauty of native plants—they practically take care of themselves! No need for fertilizer (it actually prefers low fertility), minimal watering once established, and natural pest resistance.

A Few Things to Keep in Mind

While thickstem aster is wonderfully low-maintenance, it’s not for every garden situation:

  • Short lifespan means you’ll need to allow for reseeding
  • Not suitable for formal, highly maintained landscapes
  • Foliage dies back in winter (no evergreen interest)
  • Can spread readily—great for naturalized areas, but might be too enthusiastic for small, controlled spaces

The Bottom Line

Thickstem aster might not win any beauty contests, but it’s the kind of steady, reliable garden citizen that quietly does its job year after year. If you’re gardening in the western United States and want to support native ecosystems while creating a beautiful, low-water landscape, this purple-flowered performer deserves a spot in your garden. Just give it sun, decent drainage, and the freedom to be its wild self—then step back and watch it work its understated magic.

How

Thickstem Aster

Grows

Growing season

Spring and Summer

Lifespan

Short

Growth form & shape

Multiple Stem and Erect

Growth rate

Rapid

Height at 20 years
Maximum height

3.0

Foliage color

Green

Summer foliage density

Porous

Winter foliage density

Porous

Foliage retention

No

Flowering

Yes

Flower color

Purple

Fruit/seeds

No

Fruit/seed color

Brown

Allelopath

No

Nitrogen fixing

None

Toxic

None

C:N Ratio

High

Fire Resistant

No

Foliage Texture

Coarse

Low-growing Grass

No

Resproutability

No

Coppice Ability

No

Bloat

None

Thickstem Aster

Growing Conditions

Adapted to Coarse Soil

Yes

Adapted to Medium Soil

Yes

Adapted to Fine Soil

No

Anaerobic tolerance

None

CaCO₃ tolerance

High

Cold Stratification

No

Drought tolerance

High

Nutrient requirement

Low

Fire tolerance

High

Frost-free days minimum

120

Hedge tolerance

Medium

Moisture requirement

Low

pH range

6.0 to 7.5

Plants per acre
Precipitation range (in)

10 to 60

Min root depth (in)

6

Salt tolerance

None

Shade tolerance

Intolerant

Min temperature (F)

-23

Cultivating

Thickstem Aster

Flowering season

Late Summer

Commercial availability

No Known Source

Fruit/seed abundance

High

Fruit/seed season

Summer to Fall

Fruit/seed persistence

No

Propagated by bare root

No

Propagated by bulb

No

Propagated by container

No

Propagated by corm

No

Propagated by cuttings

No

Propagated by seed

Yes

Propagated by sod

No

Propagated by sprigs

No

Propagated by tubers

No

Seed per pound

880000

Seed spread rate

Rapid

Seedling vigor

High

Small grain

No

Vegetative spread rate

Moderate

Thickstem 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

Eurybia (Cass.) Cass. - aster

Species

Eurybia integrifolia (Nutt.) G.L. Nesom - thickstem aster

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