OSC Sunflower Mammoth Russian
If you want to grow the champion sunflower for the fall fair, this heirloom variety is the one to choose! Huge, single yellow blooms ranging from 25-35 cm (10-14″) in diameter are produced on tree trunk like stems that can easily grow to 3 m (9′) or more in height! This is the best variety for feeding the birds as well as for roasting seed for yourself! Taller plants may need staking due to the weight of their mighty seed heads!