Sunflower Seeds - Mammoth Grey Stripe


Helianthus annuus

Long-blooming, large-headed, archetypal giant sunflower. Easy-to-grow. Sturdy 6-12' stalks with big yellow-petaled flowers. Often grown for their meaty seeds, good for roasting or bird seed. Direct seed in full sun after danger of frost. Summer-fall blooming. Annual.  
  • Planting Information
  • Growing Information


Approx. Seeds per Packet 
Average packet weight 
Seeds / gram 
Average seed / oz
1.75 grams
Planting SeasonIdeal Soil TempSunFrost Tolerance
After Last Frost65-85°FFull SunFrost Sensitive
Sowing MethodSeed DepthDirect Seed SpacingDays to Harvest 
Transplant or Direct Seed1"4-16"90-100
Mature SpacingDays to SproutProduction CycleSeed Viability
8-12"5-12Annual4-6 years

Site Selection


Sunflower is a frost sensitive annual that prefers full sun and well-drained soil with low to moderate moisture. Drought tolerant once established.




Direct seed outdoors once the danger of frost has passed. Optimum soil temperature for germination is 65-85˚F. Sow 1" deep and 4-6" apart. Seeds will sprout in 5-12 days. Thin so mature plants are 8-10" apart.