New set of sunflower plants thriving well!

Last time when I tried to grow sunflower plants, none of the seeds sown in garden pots germinated. Then I germinated one in a moist tissue paper and replanted in a garden pot. That plant had grown well and given a few flowers. That was a few years back. This time I used a 23 inch garden pot filled with potting mixture. Potting mixture contained soil cocopeat and possibly cow dung powder, about which I am not very sure as I bought it from a local nursery. This time I was luckier to have seven of the ten seeds sown germinate into healthy seedlings. They are in the bright sun and thriving well. Last time when the plants reached this size, tiny flower bud had appeared. But this time I am not seeing any flower buds yet. For most plants I have noted that if the growth is fast, it takes longer period to flower. May be when there is plenty of nutrition, plants focus on vegetative growth! I am quite happy to see these sunflower plants growing well and I hope that they will bloom sooner or later.