After around two months from sowing the seeds, my sunflower plants started to flower:
The photos above are of a sunfowr plant I had planted in a 40 cm (15") pot at the edge of my balcony in Cairo, Egypt.
The birds seemed to like the taste of the sunflower plant leaves so I had to hange an old CD next to the sunflower plant in order to deter them and it did turn out to be very effective.