Blue false indigo

Blue false indigo is a large, showy, shrub-like plant with gray-green leaves and 10 to 12 inch medium blue flowers in May.  The pea-like flowers are followed by black seed pods which are interesting enough to leave up over the winter.  Reliable, drought-resistant and long-lived, blue false indigo provides a strong structural presence in a garden.

This plant has a cultivated variety. Go to list of cultivars.

 

Botanical name:

Baptisia australis

All Common Names:

Blue false indigo, baptisia, blue wild indigo

Family (English):

Pea

Family (Botanic):

Fabaceae (formerly Leguminosae)

Tree or Plant Type:

  • Perennial

Native Locale:

  • North America

Landscape Uses:

  • Foundation,
  • Mixed border,
  • Specimen

Size Range:

  • Large plant (more than 24 inches)

Light Exposure:

  • Full sun (6 hrs direct light daily),
  • Partial sun/shade (4-6 hrs light daily)

Hardiness Zones:

  • Zone 3,
  • Zone 4,
  • Zone 5 (Chicago),
  • Zone 6,
  • Zone 7,
  • Zone 8,
  • Zone 9

Soil Preference:

  • Dry soil

Season of Interest:

  • Early winter,
  • Mid winter,
  • Late winter,
  • Mid spring,
  • Late spring,
  • Late summer,
  • Early fall,
  • Mid fall,
  • Late fall

Flower Color & Fragrance:

  • Blue

Shape or Form:

  • Vase-shaped

Growth Rate:

  • Slow

More Information:

 

Size

Three to four feet tall and four feet wide.  Spreads slowly by rhizome.

Plant Care

Best grown in full sun.

Plants are slow growing and do not require frequent division.

Prune back in early spring to preserve the black seed pods for winter interest in the garden.

Somewhat difficult to transplant due to a deep taproot.

Disease, pests, and problems

No serious pest problems.  Plants may require staking in part-shade.

Disease, pest, and problem resistance

Deer and rabbit resistant.  Drought-tolerant once established.

Native geographic location and habitat

Eastern United States

Attracts birds or pollinators

Butterflies and other pollinators

Leaf description

Leaves are formed by three leaflets 1.5 to 3 inches long.  Foliage is blue-green.

Flower description

Indigo blue flowers bloom in May on long, vertical stalks (racemes).  Individual flowers are about one inch long.

Fruit description

The fruit is a two to three inch pod that turns black as it matures.  It will hang on the plant all winter if the plant is not cut back.

Cultivars and their differences

Dwarf blue false indigo (Baptisia australis var. minor)Simply a smaller version of Baptisia australis, growing18-24 inches tall and wide.


Location of Baptisia australis (Blue false indigo) at the Arboretum