Rose:

Hi Rose
There are hundreds of varieties of sunflowers.  Some grow short (3-5 feet) and are branching, meaning they have many flowers from one central stem.  Others can be 12 feet tall with one giganting flower at the top and smaller flowers coming out along the stem below.  It just depends on what variety you have.  We have planted some called sunbeam, moonbright, sunbright, Van Gogh Mix,  Italian white, and lemon, just to name a few.  They can have all different colored disks and petals