Baptisie bleue
Baptisia australis
Une vivace indigène longévive des lisières forestières et des prairies du centre et de l'est des États-Unis, aux fleurs bleues profondes en forme de pois en fin de printemps, à un feuillage légumineux bleu-vert, à de jolies gousses noires offrant un intérêt hivernal, et à un système racinaire fixateur d'azote (Fabaceae). Plante hôte larvaire de 6 espèces de papillons documentées par NC State (souci tacheté, piéride d'Amérique, Callophrys irus, Cupido comyntas, Achalarus lyciades, Erynnis baptisiae) — parmi les vivaces de la flore de l'Est les plus favorables aux Lépidoptères.
Native: 29 US states
Climate fit: broad (90/100)
Border
Pollinator
Focal point
Structure
Light
Full sun / Part shade
Water
Moderate water
Mature size
36-48" tall · 36" apart
Hardy in zones
3a-9b
brutally cold to frosty winters
AHS heat range
1-11
Plant range authored in AHS heat-zone terms.
Native in Illinois
Yes
Related products
Sponsored
Heat and sun protection
Shade cloth, shade hoops, cooling mulch, and heat-stress monitoring tools.
Search heat and sun protection on Amazon ->
Plant support
Stakes, cages, trellises, ties, clips, arbors, and heavy-duty supports.
Search plant support on Amazon ->
Transplanting and establishment
Trowels, transplant spades, starter fertilizer, root stimulators, and watering bags.
Search transplanting and establishment on Amazon ->
Safety and handling
Gloves, eye protection, thorn-proof sleeves, and handling supplies for toxic plants.
Search safety and handling on Amazon ->
Soil testing and pH
pH meters, soil test kits, lab mailers, and amendment calculators.
Search soil testing and ph on Amazon ->
Propagation
Rooting hormone, propagation trays, cutting tools, division knives, and labels.
Search propagation on Amazon ->
Plotwright may earn a commission from purchases made through these links, at no extra cost to you.
A documented larval host for the Skipper butterflies — 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 41 ecoregions — 40 climate-resilient through 2070 · 1 suited today. Best matches first.
Appalachian mixed mesophytic forests
›
Appalachian-Blue Ridge forests
›
Arizona Mountains forests
›
Atlantic coastal pine barrens
›
Blue Mountains forests
›
Canadian Aspen forests and parklands
›
Central Pacific Northwest coastal forests
›
Central Tallgrass prairie
›
Central-Southern Cascades Forests
›
Chilean Matorral
›
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). Baptisie bleue (Baptisia australis). Retrieved 2026, June 14, from https://plotwright.garden/plants/baptisia-australis
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