David's Garden Seeds Sunflower Mammoth Grey Stripe OS519 (Yellow) 50 Non-GMO, Open Pollinated Seeds Blooms in 90 to 110 days Seeds are Non-GMO and hand packed by David's Garden Seeds in the United States Very large head--12 to 24 inches in width Grows to a height of 8 to 12 feet Germination rate about 80% or better