Beginner Gardening: Why did the heads of my sunflowers close and won't open?, 1 by birdstalker

birdstalker wrote:
I bought my first sunflower plant with three healthy, open flower heads. Everything was fine for a couple of weeks, then the stems started to sprout new buds next to each flower. However, the buds stopped growing and now each head has closed tightly shut . The flowers are not brown and they don't appear to be dead. If the blooms are indeed dead, what should I do next? Will they bloom again on the stalk, or must they grow new stalks in order to produce new blooms?

Can anyone enlighten me?