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Blue false indigo

Baptisia australis

Common names:
blue false indigo, baptisia, blue wild indigo

Content Detail

Blue false indigo is a large, showy, shrub-like plant with gray-green leaves and 10 to 12 inch medium blue flowers which bloom 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.

  • Family (English) Pea
  • Family (botanic) Fabaceae (formerly Leguminosae)
  • Tree or plant type Perennial
  • Native locale North America
  • 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 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9
  • Soil preference Dry soil
  • Tolerances clay soil, Dry sites, Occasional drought
  • Season of interest early winter, midwinter, late winter, mid spring, late spring, late summer, early fall, mid fall, late fall
  • Flower color and fragrance Blue
  • Shape or form Vase-shaped
  • Growth rate Slow

Size:

Blue false indigo grows 3 to 4 feet tall and 4 feet wide. It spreads slowly by rhizome.

Native geographic location and habitat:

Blue false indigo is native in the eastern United States.

Attracts birds or pollinators:

Butterflies and other pollinators are attracted to it.

Leaf or needle arrangement, size, shape, and texture:

The leaves are formed by three leaflets, 1 1/2 to 3 inches long. The foliage is blue-green.

Flower arrangement, shape, and size:

Indigo blue flowers bloom in May on long, vertical stalks (racemes). The Individual flowers are about 1 inch long.

Fruit, cone, nut, and seed descriptions:

The fruit is a 2 to 3 inch pod that turns black as it matures. It will hang on the plant all winter if the plant is not cut back.

Plant care:

It grows best in full sun. Plants are slow growing and do not require frequent division. Blue false indigo should be pruned early spring to preserve the black seed pods for winter interest in the garden. It is somewhat difficult to transplant due to a deep taproot. Plants may require staking in part-shade.

List of pests and diseases:

Blue false indigo isn’t affected by any serious pest problems. It is deer and rabbit resistant. It is also drought-tolerant once established.

Dwarf blue false indigo (Baptisia australis var. minor):

This cultivar is a smaller version of Baptisia australis and grows 18 to 24 inches tall and wide.

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