Blue False Indigo

Baptisia australis

Fabaceae · perennial · introduced

Last updated

Well-suited to Zone 8b. Deep taproot makes it very drought-tolerant once established, which is valuable during increasingly dry Puget Sound summers. Nitrogen-fixing legume; does not need fertilizer. Full sun produces best flowering. Tolerates clay soils well. Slow to establish (2-3 years to full size) but very long-lived and low-maintenance once settled. No serious pest or disease problems reported by MBG, NC State, or Clemson.

Plant Profile

Size & Form

Height
5 ft
Spread
2-4 ft
Growth Rate
Slow

Site Requirements

Light
Full Sun
Soil Drainage
Moist
Soil pH
4.5-7.0
Water
Moderate
Drought Tolerance
Moderate to high
Hardiness
Zones 3a–9b

Ornamental Interest

Bloom Time
May to June
Origin
Eastern North America
Watch for this season

Active Conidial Spread

RustHigh

Uredinial Stage (Summer)

Diseases: Other Associations (3)

Pests: Other Associations (1)

Phenological Calendar

As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Blue False Indigo has passed 'first bloom' (1638 GDD₃₂).

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Jun 3, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 2,673 'First bloom'
Kent / Auburn 2,665 'First bloom'
Seattle / UW 2,610 'First bloom'
Olympia / Tumwater 2,570 'First bloom'
Tacoma / Puyallup 2,535 'First bloom'
Bellingham / Whatcom 2,533 'First bloom'
Sequim / Rain Shadow 2,436 'First bloom'
View full calendar (1 stages)
Stage GDD32 Typical Window
'First bloom' BBCH '61' NOW 1638 ''
Range: 1018–1280 GDD₃₂ (6yr)

Source: 'Master catalog (UMD), GDD50 base' About GDD₃₂ →

Season tracker for Kent / Auburn as of Jun 3, 2026. Predicted dates use 16-day weather forecast through Jun 19, 2026, then climate normals.

Data Maturity
Baseline Extension data. Expert review underway.