Amorpha fruticosa – False Indigo Bush

General Information:  Stunning purple flowers adorn strongly dissected leaves of False Indigo Bush, a haven for pollinators and native plant gardeners alike. This shrub provides an intriguing floral display of deep purple spike flowers early in the growing season. In the southern reaches of this plant’s range, flowers can emerge as early as April, or in June in northern regions, and last for about a month. Flowering spikes are decorated with orange speckles (the emergent anthers). The two-toned floral display has a mesmerizing pattern that is sure to turn heads. The Pea-like fruits ripen in September and October.

An incredibly low-maintenance plant with an important ecological role, False Indigo Bush is known to attract a wide variety of pollinators and is a host plant for several Moth and Butterfly species. The seeds are an important winter food source for birds, especially Grouse and Quail. False indigo has been used medicinally by Indigenous Peoples throughout the plant’s native range. A blue dye can be obtained from the plant, hence the name “Indigo Bush.” An organic Rotenoid-group pesticide can be obtained by crushing the fruits.

Cultivation Details: False Indigo Bush is an exceptional companion plant to many herbaceous perennials, with foliage and flowers occurring mostly on the upper 1/3 of the plant. This plant fixes nitrogen and is useful for companion plantings, especially in nutrient-poor soils. False Indigo Bush performs exceptionally well in poor soils and does not require soil amendments to thrive. Their root systems are extensive, which often precludes them from transplanting easily once established. These plants spread readily by suckers, eventually forming thickets. Trim back new growth or root prune established plants if a more compact planting is desired. While this plant is considered native to much of North America, the plant has been introduced to the Northeast and Pacific Northwest. Growers in these areas should take care to limit the spread of this plant by seed. Spent flower spikes can be removed to eliminate the concerns of unwanted seed dispersal. Consider pairing with native herbaceous perennials, native vines, and native prairie grasses. Ideal for rewilding, pocket prairies, living fences, border plantings, or planting along roadsides

Growing Requirements: Plant in full sun to part shade. Uniquely tolerant of almost all soil types. Especially tolerant of heavy clay soils, very sandy soils, and wet soils. Suitable for most soil pH. Uniquely tolerant of very acidic and very alkaline soils.

Fun Facts: The genus Amorpha is the type-genus for the Amorpheae tribe of the Pea Family, Fabaceae. Plants in this subsection all have unique flowers with only one petal, compared to the usual floral structure found in other members of the Pea Family. They are considered amorphous, or misshapen, by botanists.