False Indigo is a deciduous native shrub in the Fabaceae (bean) family. It is typically found growing in moist open woodlands, roadsides, canyons, floodplains, gravel bars, stream and pond banks, and along swamp edges. The genus name Amorpha is Greek meaning "formless or deformed" and refers to the flowers which having only one petal are very different from other members of the pea family. Plant in the full sun to partial shade moist to dry soil. It is tolerant of a large range of soil types including wet ones. The pinnately compound leaves are clustered on the upper third of the plant and give it a fine texture and an airy appearance. It spreads easily by seeds and suckers, and can form dense thickets. The horizontal growth creates a situation where its spread will often be greater than its height. Use this plant in a woodland or bog garden, along a pond margin or stream bank. It looks best when grouped in mass plantings. Insects, Diseases and Other Plant Problems: Typically has no serious disease or insect issues. Leaf spot, powdery mildew, rust, and twig canker are diseases that may have some effect on the plants' overall health. VIDEO created by Grant L. Thompson for “ Trees, Shrubs, and Woody Vines for Landscaping ” a plant identification course offered by the Department of Horticulture at Iowa State University .
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; High Organic Matter; Loam (Silt); Sand
Soil pH
Acid (<6.0); Neutral (6.0-8.0)
Soil drainage
Moist | Occasionally Dry | Occasionally Wet
Available space
12-24 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 4 ft. 0 in. - 15 ft. 0 in. | Width: 6 ft. 0 in. - 15 ft. 0 in.
Growth rate
Rapid
Maintenance
Low
Canopy layer
2 - Understory (15-40 ft)
Form & Appearance
Habit / form
Dense; Horizontal; Spreading
Texture
Fine
Foliage
Deciduous
Leaf color
Gray/Silver; Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately)
Leaf arrangement
Alternate
Leaf shape
Elliptical; Oblong; Ovate
Leaf margin
Entire
Leaf feel
Velvety
Leaf value
Fragrant
Leaf size
1-3 inches long, < 1 inch wide
Hairs present
No
Leaf detail
The leaves dull gray-green. Each contains 13 to 33 spiny-tipped leaflets with toothless margins. The leaflets are elliptic to oval in shape with a notch at the tip. They turn a modest yellow in the fall (fall color). The underside of the leaves has a velvety feel.
Fall color
Gold/Yellow
Flower color
Blue; Gold/Yellow; Purple/Lavender
Flower value
Fragrant; Showy
Flower form
Raceme
Flower shape
Tubular
Flower size
3-6 inches
Flower detail
Each flower has a single petal and is very much unlike other flowers in the pea family. This plant has narrow, 8 to 20 in. racemes of dense, clusters of deep purple or blue flowers with gold stamens in summer. The blooming period is 2-3 weeks any time from April to June.
Bloom time
Spring; Summer
Fruit color
Brown/Copper
Fruit type
Legume
Fruit value
Showy
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
Small, warty, kidney-shaped seed pods
Bark color
Dark Gray; Light Brown; Light Gray
Bark detail
Relatively smooth, scattered lenticels.
Stem color
Green
Stem detail
Multi-stemmed. The lower stems are woody. Upper stems are dull green.
Wildlife & Ecology
Native status
Native
Origin
Southern United States
Distribution
AL, AR, AZ, CA, CO, CT, DC, DE, FL, GA, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NC, ND, NE, NH, NJ, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, WA, WI, WV, WY
Wildlife value
Flowers attract butterflies, nectar-bees, and other pollinator insects. It is a larval host for the California & southern dogfaces, Silver-spotted Skipper (Epargyreus clarus), Gray hairstreak, Hoary edge skipper. Foliage browsed by small mammals.