Since the bunnies chomped on this year’s crop of sunflowers, I had to look back a few years to find these pictures. These are Mammoth Gray Stripe Sunflowers which can grow 9-12 feet tall and flowers with a diameter of around 14 inches. While ours didn’t grow quite that big, I’d say they were between 6-8 feet tall. The flowers themselves were very large though I didn’t measure them. I keep a few of the blooms in a paper bag over the winter months, and then I use the seeds to replant. This normally works fine, but the bunnies thwarted my plans.