perennial
Blue false indigo
Baptisia australis
Preview: plant data is awaiting horticulturist review. A professional horticulturist hasn't reviewed our plant table yet. Lists still follow fixed rules for zone, sun, pets, deer and invasive status.
Hardy in zones 3–9, Blue false indigo is a slow-growing perennial. Expect 3–4 ft of height and 3–4 ft of spread; our lists space it 3.5 ft apart. It does best in full sun to part sun with little water once established. Expect blue flowers in May to June. In a FloraVista list it usually plays the filler role: a flowering plant that fills the middle or front of the bed. It is native to the Mid-Atlantic, the Southeast, the Midwest, the Great Plains and Texas and the South-Central states. Deer usually leave it alone, and it is toxic to dogs and cats. Our rules leave it out of lists in Florida and the Gulf and the Desert Southwest, where summer heat, humidity or mild winters hold it back even inside its zone range.
Facts from our plant table
- Botanical name
- Baptisia australis
- Plant type
- Perennial, herbaceous
- Hardiness zones
- 3 to 9
- Sun
- Full sun (6+ hours); Part sun (4–6 hours)
- Water
- Low
- Soil
- Any well-drained soil; deep taproot, do not move once planted.
- Mature size
- 3–4 ft tall × 3–4 ft wide
- Spacing
- 3.5 ft apart (centre to centre)
- Growth rate
- Slow
- Bloom
- May–Jun · blue
- Roles in a bed
- Filler
- Styles
- natural, cottage, low water
- Deer resistance
- High: deer rarely eat it
- Pets
- Toxic to dogs and cats. Not on the ASPCA list; contains quinolizidine alkaloids. Marked toxic as a precaution.
- Native to
- Mid-Atlantic, Southeast, Midwest, Great Plains and South-Central
- Pot size and price
- 1-gallon pot, typically $15–$25 (easy to find)
- Plant in
- Spring or Fall
- First-year watering
- Water weekly through the first summer until roots establish, then only during long dry spells.
- Pruning
- Leave seed pods for interest; cut down in late winter.
Sources: ASPCA Toxic and Non-Toxic Plant List (from general knowledge; not re-checked unless verification is web-checked); Missouri Botanical Garden Plant Finder and grower tags; State extension service guidance and USDA PLANTS distribution maps; Rutgers NJAES Landscape Plants Rated by Deer Resistance; Invasive Plant Atlas of the United States and state noxious weed lists; Typical 2026 US garden-centre and big-box retail listings (estimate). Not yet reviewed by a horticulturist.
Guides that include this plant
- Deer-resistant plants for a full-sun bed in zone 4
- Deer-resistant plants for a full-sun bed in zone 5
- Low-water plants for a full-sun bed in zone 7
- Low-water plants for a full-sun bed in zone 8 (as a substitute)
- What to plant in a full-sun bed in zone 4 (as a substitute)
- What to plant in a full-sun bed in zone 7
- Cottage garden plants for a sunny bed in zone 6
- Natural-style plants for a sunny bed in zone 7 (as a substitute)
Good companions
The plants our list engine most often puts in the same bed as Blue false indigo, across the sun, zone, pet, deer and style combinations it fits.
- Shrubby cinquefoil (potentilla) 'Goldfinger'Dasiphora fruticosa 'Goldfinger'shrub · zones 2–7
- Arrowwood viburnum 'Blue Muffin'Viburnum dentatum 'Christom'shrub · zones 3–8
- Lamb's ear 'Helen von Stein'Stachys byzantina 'Helen von Stein'perennial · zones 4–8
- Blue fescue 'Elijah Blue'Festuca glauca 'Elijah Blue'ornamental grass · zones 4–8
- Meadow sage 'May Night'Salvia nemorosa 'May Night'perennial · zones 4–8
- Pink muhly grassMuhlenbergia capillarisornamental grass · zones 6–11
If you can't find it
Substitutes our engine offers for Blue false indigo: same role in the bed, passing the same rules.
How this page was made
This page was generated from this plant's record in FloraVista's plant table by fixed rules. The companions and substitutes come from the lists our rules engine composes. No named expert has reviewed this page.
Data status: the plant table is awaiting review by a horticulturist. Check each plant with a local nursery or extension office before you buy.
Sources
- Missouri Botanical Garden Plant Finder, state extension services and the USDA PLANTS database (zones, size, sun, water, bloom, native range)
- ASPCA toxic and non-toxic plant lists (dog and cat toxicity)
- Rutgers NJAES and regional extension deer-resistance ratings
- State noxious-weed and invasive-plant lists and the Invasive Plant Atlas of the US
- Typical US garden-centre listings (pot size and price band)
Generated . How FloraVista chooses plants