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Manitoba Museum

Aster (Asteraceae)

Smooth Aster

Symphyotrichum laeve (L.) A. & D. Löve

The attractive blue and yellow flowers of this prairie perennial are fragrant. They are pollinated by insects, commonly attracting butterflies, bees, flies, and beetles. Plants are often foraged upon by deer and some butterfly larvae who favour the bright green foliage. This Aster reproduces by spreading its wind-dispersed seeds or by sprouting underground rhizomes, which occurs easily after a fire.

Flower Colour:

  • Blue

Flowering Season:

  • Summer
  • Fall

Flowering Months:

  • August
  • July
  • October
  • September

Canadian Rarity Status:

Not rare. Listed as “exotic” in Quebec.

Physical Appearance:

The erect, branching stems grow 30-120 cm tall. Egg-shaped stem leaves are alternate and unstalked, with smooth or shallow-toothed edges. Basal leaves are stalked and senesce before flowering. Few to many small flower heads occur in open clusters near the ends of branches. Each head is backed by 4-5 whorls of pointy bracts and consists of 15-30 blue ray florets surrounding 35-40 yellow disc florets. Fruits are dark brown, single-seeded achenes, topped by a tuft of bristles.

Similar Species:

Lindley's Aster, Western Silvery Aster

Gardening Notes:

Seeds and/or plants are often available from greenhouses and seed supply companies specializing in native plants. Makes a good addition to butterfly, bird, and prairie gardens.

Canadian Distribution:

  • Alberta
  • British Columbia
  • Manitoba
  • New Brunswick
  • Ontario
  • Quebec
  • Saskatchewan
  • Yukon

Prairie Types:

  • Fescue Prairie
  • Mixed Grass Prairie
  • Tall Grass Prairie


  • Alvars
  • Forest Edges
  • Open Woodlands
  • Prairies
  • Savannahs

Moisture Conditions:

  • Dry

Light Preference:

  • Full Sun

Soil Preference:

  • Clay
  • Sand
Smooth Aster