St Charles County Master Gardeners
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Blue False Indigo (Baptisia australis)
Species Native to Missouri
Common Name: blue false indigo
Type: Herbaceous perennial
Native Range: Eastern United States
Zone: 3 to 9
Height: 3.00 to 4.00 feet
Spread: 3.00 to 4.00 feet
Bloom Time: May to June
Bloom Description: Indigo blue
Sun: Full sun to part shade
Water: Dry to medium
Suggested Use: Naturalize
Tolerate: Rabbit, Drought, Erosion, Clay Soil, Dry Soil, Shallow-Rocky Soil
Easily grown in average, dry to medium, well-drained soil in full sun to part shade. Best in full sun. Tolerates drought and poor soils. Over time, plants develop slowly expanding clumps with deep and extensive root systems, and should not be disturbed once established. May be grown from seed, but takes several years to establish. Plants take on more of a shrubby appearance and tend to open up after bloom. Trimming or shearing foliage after bloom helps maintain rounded plant appearance and obviates a possible need for staking, but eliminates the developing seed pods which are so attractive.
Blue false indigo is an upright perennial which typically grows 3-4' tall and occurs in rich woods, thickets and along streambanks from Pennsylvania south to North Carolina and Tennessee. It features purple, lupine-like flowers in erect racemes (to 12") atop flower spikes extending well above a foliage mound of clover-like, trifoliate, bluish-green leaves (leaflets to 2" long). Blooms in spring. Flowers give way to inflated seed pods (to 2.5" long) which turn charcoal black when ripe and have considerable ornamental interest. Seeds rattle around in the blackened pods which were once popularly used by children as rattles. Stems with seed pods are valued additions to dried flower arrangements. Common name refers to the use of this plant by early Americans as a substitute, albeit an inferior one, for true indigo (genus Indigofera of the West Indies) in making blue dyes. The smaller western form, Baptisia australis var. minor, is a Missouri native which typically grows to about 1/2 the size of the species. It ranges from Missouri and Kansas south to Texas.
No serious insect or disease problems. Taller plants may need support, particularly when grown in part shade locations.
Borders, cottage gardens, prairies, meadows and native plant gardens. Effective in naturalized settings. Best as a specimen or in small groups.