Sunflowers are amazing. In just a short time span they grow to 10 feet tall and then produce a magnificent bloom.
Here is the long view and you can see how tall they are. The blooms are in various stages - some have not yet opened, some are in the process, and one (nearly hidden) is bent over with the weight of the developing seeds.
It is fascinating to watch the process. The little blossoms open first on the outside rim, then work their way towards the center. The bees and the butterflies love them!
You can see here the outside blossoms have been fertilized and are growing seeds. The next band is the pistils that have just been fertilized. The next band is waiting for the bees to do their job, and the very center has not yet begun the process.
As the blossoms get fertilized and the seeds begin to develop, the head of the flower goes from flat to bowl shaped, and gets heavier and heavier.
This head has been entirely fertilized and is so heavy that the stalk has bent over and the flower is facing the ground. It will take several weeks for the seeds to develop. Once that is done, I can leave the head on the plant and let the birds eat the seeds from there. Or I can cut the head and hang it to dry, and then harvest the seeds. Last year I cut the heads off but I think that this year I will leave them out and watch the birds go after them.