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: 47 US states + 9 CA provinces
Climate fit: broad (80/100)
Pollinator
Border
Light
Full sun
Water
Moderate water
Mature size
24-48" 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...
Where this plant fits
Suitable across 40 ecoregions — 35 climate-resilient through 2070 · 5 suited today. Best matches first.
Appalachian mixed mesophytic forests
›
Appalachian-Blue Ridge forests
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Arizona Mountains forests
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Blue Mountains forests
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Canadian Aspen forests and parklands
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Central Pacific Northwest coastal forests
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Central Tallgrass prairie
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Central-Southern Cascades Forests
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Colorado Rockies forests
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Cross-Timbers savanna-woodland
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Similar plants
Browse lateral options with similar roles, light needs, size, or native-range overlap; these are not filtered for a better climate fit.
Agastache foeniculum
Anise hyssop
An upright, clump-forming perennial of the mint family native to the upper Midwest, Great Plains, and into central Canada, named for its anise-scented foliage. From June through September it carries dense terminal spikes of lavender-to-purple two-lipped flowers above square stems and opposite, toothed leaves. The Lady Bird Johnson Wildflower Center flags it as a nectar source with special value to native bees, bumble bees, and honey bees, and it also draws butterflies and hummingbirds.
Symphyotrichum oblongifolium
Aromatic aster
A native central + eastern US perennial with intensely aromatic foliage when crushed and dense clouds of small blue-purple flowers in late fall — often the latest-blooming aster in the eastern flora. Drought + clay tolerant; among the toughest native fall pollinator plants.
Rudbeckia fulgida
Black-eyed Susan
A tough, bright perennial for sunny borders, pollinator patches, and late-summer color.
Baptisia australis
Blue false indigo
A long-lived native perennial of central and eastern US woodland borders and prairie meadows with deep blue pea-shaped flowers in late spring, blue-green leguminous foliage, attractive black seed pods for winter interest, and a nitrogen-fixing root system (Fabaceae). Larval host for 6 documented butterfly species per NC State (orange sulphur, clouded sulphur, frosted elfin, eastern tailed-blue, hoary edge, wild indigo duskywing) — among the highest Lep-host-count perennials in the eastern flora.
Verbena hastata
Blue vervain
A native vervain of eastern and central North American wet meadows, stream banks, and rain gardens — a rough, clump-forming perennial with stiff, square hairy stems that branch above into candelabra-like spires. Slender, pencil-like spikes carry tiny purplish-blue tubular flowers that open a few at a time from the bottom up over a long July-to-September bloom. Attracts hummingbirds and butterflies and carries Special Value to Native Bees.
Epilobium canum
California fuchsia
A drought-hardy western-native subshrub (long known as Zauschneria) that lights up dry, rocky ground with scarlet tubular flowers from midsummer until frost — exactly when migrating and resident hummingbirds need a late-season nectar source. Slender, highly-branched stems carry small grey-green lance-shaped leaves; the whole plant thrives on full sun, lean soil, and very little water once established.
Appears in collections
Collection · 9 plants
Native pollinator border (eastern US)
A continuous-bloom native pollinator strip for eastern North America. Covers spring through frost with host + nectar plants spanning monarchs, native bees, hummingbirds, and specialist Lepidoptera. Little bluestem provides the matrix grass + Hesperiidae host.
Sources & citations
Cite this page
For lesson plans, articles, or research that uses this page. To cite a single upstream fact instead, use its specific source listed below.
Plotwright. (2026, May 17). Smooth blue aster (Symphyotrichum laeve). Retrieved 2026, June 24, from https://plotwright.com/plants/symphyotrichum-laeve
Sources for every fact
Every fact on this page traces to a source. 18 fields cited - 18 source-backed.
NC State Extension Gardener Plant Toolbox
University extension service
Backs 17 fields
Identity
Summary
Plant type
Light
Moisture
Hardiness
Heat zone
Size
Spacing
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