Mammoth Gray Grey Stripe HUGE Sunflower - Seed Seeds - 9-12 Feet Tall - EXTENDED BLOOMS - Zones 1-10 - By MySeeds.Co (1100 Seeds - 4 oz) Mammoth Gray - Grey Stripe HUGE Sunflower Seeds ~ 9- 12 Feet Tall Extended Bloom Sunflower Seeds - Mammoth Gray Stripe Common Name Sunflower Botanical Name Helianthus annuus Cycle Annual Color Yellow Height 96"-144"tall (8-12 feet) Origin Native Germination Time 10-20 days depending on soil and weather conditions. Planting Season Spring/ Fall Bloom Season Summer Light Requirements Full Sun, Mostly Sunny, Half Sun / Half Shade Soil Moisture Dry, Average, Moist/Wet, Well Drained Will Tolerate Sandy Soil, Loamy Soil, Clay Soil, Moist/Wet Soil, Drought/Dry Soil Ideal Growing Region All regions of North America Zones 1-10 Other Information Hedge / Screen, Showy Flowers, Extended Blooms, Easy to Grow