The indigo dye comes from a leguminous plant of the Indigofera genus, of which over three hundred species have been identified. Only two species are named frequently in the commercial history of the dye, namely: indigofera tinctoria (native to India and Asia) and indigofera suffructiosa (native to South and Central America).Indigo plants have a single semi-wood stem, dark green leaves that are oval-shaped in most species, and clusters of red flowers that look like butterflies and turn into peapods. The plants can grow from two to six feet in height and the dye is obtained mainly from the leaves through a process of fermentation.



The land is prepared for the crop in October-November and the number of ploughings and harrowing depend largely on the nature of soil. On the high sandy loams few ploughings may suffice, while one may be deemed necessary on low lying clays. Indigo is sown at the commencement of the hot season Viz: February - March. The seed is drill-sown at the rate 10 to 20 kg per acre. February is the ideal month for sowing of this crop. Crop was found giving good foliage even with a half bag of DAP and a bag of urea per acre with normal irrigation. Two cuttings are obtained in July- August and second in September.

The shoots are hand reaped. Crop should be reaped when the plants begin flower. However, with the intention of reaping crop with seeds the indigo grower of Bihar was found cutting indigo crop loaded with mature and dried pods having very small seeds, during the 3rd week of September. On the removal of second cutting of shoots, the land is prepared either for the rabi crop or a fresh sowing of Indigo. For obtaining leaves reaped shoots are kept under shade where they are dried, and the leaves thereafter beaten from the twigs.



Indigo leaves can be used as a hair colouring matter can substitute the existing synthetic hair colour which is 100% natural and would not have any side effects.