False Indigo, Amorpha  fruticosa

False Indigo

Amorpha fruticosa

Benefits:
Sun Shade:
Bloom Time: Spring
Zones: 4, 5
Soil Conditions: Loam
Soil Moisture: Medium, Moist, Wet
Color: Orange, Purple
Fragrance: Yes
Height: 4 to 12 feet
Spacing: 15 feet


Description

False Indigo (Amorpha fruticosa) is a deciduous shrub that typically grows to 4-12 feet tall with a spread often in excess of its height. It is native to moist open woodland areas, floodplains, stream banks and swamp margins. It features compound, odd-pinnate leaves (each to 12 inches long). Each leaf contains 11 to 35 spiny-tipped, oval to elliptic, dull gray-green leaflets (to 2 inches long) with glandular dots and toothless margins. Tubular scented flowers (each to 3/8-inch long) bloom in May-June in dense, spike-shaped clusters (racemes) to 8 inches long. Each flower has a single-petaled purple corolla and 10 protruding stamens with showy orange-yellow anthers. Flowers are followed by fruits in small, resinous-dotted, 1-2 seeded pods (to ½-inch long) which mature in July and August. The seedpods are obovoid and somewhat flattened, terminating in short beaks; their outer surfaces are glandular-punctate. The root system is woody and branching. Sometimes small colonies of plants develop at favorable sites.

False Indigo adapts to different kinds of soil, tolerating occasional flooding. With the assistance of symbiotic bacteria, it fixes nitrogen in the ground. Habitats include riverbanks, soggy thickets, open bottomland woodlands, edges of marshland, and wet prairies along rivers. It is likely that populations of this shrub have been declining because of habitat destruction.

Easily grown in average, medium to wet, well-drained soils in full sun to light shade. Tolerant of occasional flooding. Also tolerates poor, sandy, somewhat dry soils. May spread by self-seeding and/or suckers to form thickets. It is considered weedy/invasive in some parts of its range, particularly in the northeastern and northwestern U.S.

Plant Notes and Herbal Uses
  Prune in late winter to early spring for purposes of improving shrub form.
Further Information

Wild Ones of the Fox Valley Area
Prairie Nursery
Wisconsin DNR
Wisconsin Native Plant Nurseries