Native Plants

Common Blue Wood Aster

Symphyotrichum cordifolium

USDA symbol: SYCO4

perennial forb

Canada: native
Lower 48 states: native

When most flowers are calling it quits for the season, the Common Blue Wood Aster (Symphyotrichum cordifolium) is just getting started! This delightful native perennial brings a cloud of tiny blue-purple stars to your garden right when pollinators need it most. If you’re looking for a low-maintenance plant that works ...

Common Blue Wood Aster: Your Garden’s Late-Season Pollinator Hero

When most flowers are calling it quits for the season, the Common Blue Wood Aster (Symphyotrichum cordifolium) is just getting started! This delightful native perennial brings a cloud of tiny blue-purple stars to your garden right when pollinators need it most. If you’re looking for a low-maintenance plant that works overtime for wildlife, this woodland beauty might just become your new favorite.

What Makes Common Blue Wood Aster Special?

This charming native forb is like the reliable friend who shows up when everyone else has gone home. Standing up to 5 feet tall, it produces masses of small, light blue to purple flowers that create an almost ethereal, cloud-like effect in late summer and fall. The heart-shaped leaves (that’s where the cordifolium comes from – it means heart-leaved) provide attractive texture throughout the growing season.

As a true North American native, Common Blue Wood Aster has been supporting local ecosystems for millennia. It’s found naturally across an impressive range, thriving in states from Maine down to Florida and stretching west through the Great Plains, plus several Canadian provinces including British Columbia, Manitoba, New Brunswick, Nova Scotia, Ontario, Prince Edward Island, and Quebec.

  • Species observed
  • No observations

Why Your Garden (and Local Wildlife) Will Love It

Here’s where this plant really shines: it’s a late-season superstar for pollinators. While other flowers are fading, Common Blue Wood Aster provides crucial nectar when butterflies, bees, and other beneficial insects are desperately seeking fuel for winter preparation or migration. It’s like running a 24-hour diner for the pollinator community!

The plant spreads slowly by rhizomes, making it perfect for naturalizing in woodland settings without being aggressive. Its moderate growth rate means you won’t be constantly battling an overly enthusiastic spreader, but you will enjoy a gradually expanding colony over time.

Perfect Garden Situations

Common Blue Wood Aster is incredibly versatile, but it really excels in:

  • Woodland gardens and shaded borders
  • Native plant gardens and naturalized areas
  • Rain gardens and areas with variable moisture
  • Late-season pollinator gardens
  • Low-maintenance landscape areas

This adaptable plant works beautifully as a backdrop for shorter woodland plants or as a mid-border filler that provides late-season interest when many perennials are winding down.

Growing Conditions and Care

One of the best things about Common Blue Wood Aster is its easy-going nature. Here’s what it prefers:

Light: Partial to full shade (it’s actually shade intolerant according to technical specs, but performs well in dappled woodland conditions)

Soil: Adaptable to coarse and medium-textured soils with a pH between 5.7 and 7.5. It’s quite drought tolerant once established and has low to moderate moisture needs.

Hardiness: Thrives in USDA zones 3-8, tolerating temperatures as low as -38°F

Space: Plant 2,700 to 11,000 plants per acre for restoration projects, or space individual plants about 2-3 feet apart in home gardens

Planting and Care Tips

Getting started with Common Blue Wood Aster is refreshingly straightforward:

  • Plant in spring after the last frost, ensuring at least 90 frost-free days ahead
  • Seeds can be direct sown or started from bare root plants
  • With about 2 million seeds per pound, a little goes a long way if you’re starting from seed!
  • Once established, this perennial requires minimal care
  • It may self-seed slowly, so don’t be surprised to find new plants popping up nearby
  • The plant has low seedling vigor, so be patient with young plants
  • Mature plants can be divided every few years to manage spread or create new plantings

A Few Things to Keep in Mind

While Common Blue Wood Aster is generally wonderful, there are a few considerations:

The plant has a relatively short lifespan for a perennial, but it compensates by self-seeding and spreading via rhizomes. It’s not particularly fire-resistant, so if you’re in a fire-prone area, consider its placement carefully. The fall flowers are quite conspicuous (in a good way!), but the seeds aren’t particularly showy.

Commercial availability is currently limited to contracting only, which means you might need to seek out specialized native plant nurseries or participate in seed collection programs.

The Bottom Line

Common Blue Wood Aster is one of those plants that quietly does its job while providing outsized benefits to your local ecosystem. It’s not the flashiest plant in the garden, but its late-season blooms are absolutely crucial for pollinator survival. Plus, with its low maintenance requirements and adaptable nature, it’s perfect for gardeners who want maximum wildlife impact with minimal fuss.

If you’re looking to support native biodiversity while adding ethereal late-season beauty to your woodland or shaded areas, Common Blue Wood Aster deserves a spot on your must-have list. Your local butterflies and bees will definitely thank you!

Symphyotrichum cordifolium is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Symphyotrichum cordifolium is also known as:

Aster cordifolius | USDA symbol: ASCO4
Aster cordifolius var. furbishiae | USDA symbol: ASCOF2
Aster cordifolius var. incisus | USDA symbol: ASCOI
Aster cordifolius var. lanceolatus | USDA symbol: ASCOL3
Aster cordifolius var. moratus | USDA symbol: ASCOM3
Aster cordifolius var. polycephalus | USDA symbol: ASCOP2
Aster cordifolius var. racemiflorus | USDA symbol: ASCOR
Aster cordifolius var. sagittifolius | USDA symbol: ASCOS3
Aster cordifolius ssp. sagittifolius | USDA symbol: ASCOS5
Aster finkii var. moratus | USDA symbol: ASFIM

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

How Common Blue Wood Aster Grows

Growing season

Spring, Summer, Fall

Lifespan

Short

Growth form & shape

Rhizomatous and Erect

Growth rate

Moderate

Height at 20 years
Maximum height

5.0

Foliage color

Gray-Green

Summer foliage density

Moderate

Winter foliage density

Moderate

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

Medium

Fire Resistant

No

Foliage Texture

Medium

Low-growing Grass

No

Resproutability

No

Coppice Ability

No

Bloat

None

Common Blue Wood Aster Growing Conditions

Adapted to Coarse Soil

Yes

Adapted to Medium Soil

Yes

Adapted to Fine Soil

No

Anaerobic tolerance

None

CaCO₃ tolerance

Medium

Cold Stratification

No

Drought tolerance

Medium

Nutrient requirement

Medium

Fire tolerance

High

Frost-free days minimum

90

Hedge tolerance

None

Moisture requirement

Low

pH range

5.7 to 7.5

Plants per acre

2700 to 11000

Precipitation range (in)

16 to 50

Min root depth (in)

10

Salt tolerance

None

Shade tolerance

Intolerant

Min temperature (F)

-38

Cultivating Common Blue Wood Aster

Flowering season

Summer

Commercial availability

Contracting Only

Fruit/seed abundance

Medium

Fruit/seed season

Fall to Fall

Fruit/seed persistence

Yes

Propagated by bare root

Yes

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

2000000

Seed spread rate

Slow

Seedling vigor

Low

Small grain

No

Vegetative spread rate

Moderate

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Asteridae
Order: Asterales
Family: Asteraceae Bercht. & J. Presl - Aster family
Genus: Symphyotrichum Nees - aster

Species: Symphyotrichum cordifolium (L.) G.L. Nesom - common blue wood aster

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