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Smooth blue aster

Smooth blue aster

Symphyotrichum laeve
A native North American perennial with smooth blue-green foliage and clouds of small blue-violet starry flowers in fall. Tolerates drought + clay; among the most adaptable native fall asters for residential landscapes.
Native: 45 US states + 8 CA provinces
Climate fit: broad (80/100)
Pollinator
Border
Light
Full sun
Water
Moderate water
Mature size
2-4 ft tall · 24" apart
Hardy in zones
4a-8b
very cold to frosty winters
AHS heat range
1-11
Plant range authored in AHS heat-zone terms.
Native in Illinois
Yes

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A documented larval host for the Pearl crescent - caterpillars feed on its foliage before becoming the next generation.

Cold hardiness

These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.
Now
Zone 6b
Plotwright
USDA Zone 6b
-5°F to 0°F
Well-suited
Zone 7a
Plotwright
0°F to 5°F
Well-suited
In plain terms: This location has cold winters. Its winters are projected to keep warming through 2050.
Well-suited today and still thriving in 2050.

Heat tolerance

Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.
Loading AHS heat-zone data for this location...

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Educator packet

Plant packet
Smooth blue aster educator packet
A native North American perennial with smooth blue-green foliage and clouds of small blue-violet starry flowers in fall. Tolerates drought + clay; among the most adaptable native fall asters for residential landscapes.
Scientific name
Symphyotrichum laeve
Plant type
perennial
Hardiness
4a-8b
Light
full-sun
Moisture
moderate
Spacing
24 inches
Classroom prompts
- Which plant traits are observations, and which are care recommendations?
- How would this plant fit change if the garden location moved warmer, colder, wetter, or drier?
- Which source-backed facts would you cite in a lesson handout?
Use the Sources & citations section below for page citation styles and the field-level source list.

Sources & citations

Cite this page
For lesson plans, articles, or research that uses this page. Use the source cards below to explore the references that informed this record.
Plotwright. (2026, May 17). Smooth blue aster (Symphyotrichum laeve). Retrieved 2026, August 20, from https://plotwright.com/plants/symphyotrichum-laeve
Sources used for this record
This record is compiled from the sources below.
NC State Extension Gardener Plant Toolbox
University extension service
USDA PLANTS Database
Government data source
Lady Bird Johnson Wildflower Center Native Plant Database
Botanical research database
GBIF
Botanical research database
Wikimedia Commons
Photo · CC0