Habit (mature) - aarongunnar / Wikimedia Commons - CC BY 4.0
Limited coverage
Aromatic aster
Symphyotrichum oblongifolium
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.
Native: 28 US states
Climate fit: broad (83/100)
Pollinator
Border
Light
Full sun
Water
Moderate water
Mature size
18-36" tall · 24" apart
Hardy in zones
3a-8b
brutally 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
Future
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
USDA
Published baseline for this location from 1991-2020.
Source: USDA Plant Hardiness Zone Map 2023 (1991-2020 climatology) via ArcGIS FeatureServer
Well-suited
2050
Zone 7a
Plotwright
Projected zone for this same location in 2050 (2041-2070) using SSP3-7.0 (regional rivalry).
Well-suited
In plain terms: This location is in Zone 6b today. Its hardiness profile is cold winters, and coldest nights are typically around -3°F. By 2050, the projected hardiness zone is Zone 7a based on SSP3-7.0 (regional rivalry). That is a +0.5-zone shift from Zone 6b to Zone 7a by 2050.
✓
Well-suited today and still thriving in 2050.
Heat tolerance
Future
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
›
Central Tallgrass prairie
›
Central-Southern Cascades Forests
›
Colorado Rockies forests
›
Cross-Timbers savanna-woodland
›
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). Aromatic aster (Symphyotrichum oblongifolium). Retrieved 2026, June 14, from https://plotwright.garden/plants/symphyotrichum-oblongifolium
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
Habit
Design roles
Seasonal interest
Growth stages
Lifecycle
Regional guidance
Success tips
Designer notes