A house I walk by frequently has sunflowers growing in front. At the beginning of August, there was only one that had grown tall (but not full height) and its interior of seeds was not yet complete:
Late in the month, when I went back again, I was amazed especially by this gigantic one so bursting with seeds that there seemed to be barely room for its petals!
Here is the tangle of sunflowers as they looked a few days ago (notice the difference in height from the beginning of the month to the end!):