About 6 to 10 days before flowering, the boot forms a bulge in the sheath of the flag leaf (uppermost leaf).

This stage is called boot leaf stage. Sorghum usually flowers 55 to 70 days.

                                    Panicle initiation

The flowering structure (inflorescence) in sorghum is called as panicle or head.                          
In cultivated sorghums, the panicle starts developing from 30 to 40 days after germination.
The tiny panicle can be observed by carefully cutting the stem of a 30 t0 40 days plant.          

Two days after the emergence of the inflorescence from the boot, the flowers begin to open.
The flowering can be observed from the yellow pollen from the anthers on the panicle (sorghum head). The maximum flowering takes place on 3rd or 4th day. It takes 6 days for the whole inflorescence to complete flowering.