Indigofera arrecta is a species of flowering plant in the family Fabaceae and widely distributed throughout the African continent from Senegal to Somalia, south to South Africa, and also extending into Arabia. It also has been introduced to the Indian Subcontinent, Southeast Asia, some of the islands of Indonesia, or the Philippines. Indigofera arrecta is sometimes also referred to as Natal, Bengal, or Java Indigo. It is a large, copiously-branched shrub growing up to 3 m tall.
Indigofera arrecta is a perennial plant but often cultivated as an annual. It prefers a hot, moist climate and full sun. Today it is occasionally used as a cover crop and green manure crop, but historically it was an important source of Indigo dye with a high indigo content.
The seeds have a hard seed coat and must be scratched. This can be done by soaking them for 12 – 24 hours in warm water. By this time they should have imbibed moisture and swollen. Germination takes about 4 days. The branches are harvested usually early in the morning when the plants are 4-5 months old. About 3 – 4 months later the plants can be cut again. Under ideal climatic conditions, the plant can be harvested three times a year.