20 seeds. 90-100 days to seed. Helianthus annuus. Annual.
 
Sunflower 'Mongolian Giant' is gigantic in every way. The stalks have a towering hight of 10 to 14 feet and seeds that are three times the size of any of the other varieties we sell. The sunflower heads are very large and continue to grow in breadth as the seeds mature. Mongolian giant has golden yellow flowers with green to yellow centers. Non-branching type.
 
2025 was my first time growing giant sunflowers. The flower heads became increasingly top heavy in late season, and after a heavy rain the plants uprooted themselves in the rocky soil near my house. However, I was able to save the sunflowers by putting some soil around them and tying the stems to some heavy duty hog paneling. I would suggest growing these sunflowers near some posts or fence so that they may be supported as the seed heads mature.
 
Harvesting Sunflower Seeds:
 
Store sunflower heads in a dry place when the seeds start to loosen in the sunflower head. I like to hang the sunflower heads upside down in our basement. This way the seeds can fully dry away from birds or rodents. To harvest rub the sunflower heads together and the seeds will come away easily. Blow in front of a fan outside to get rid of the seed chaff and empty seed hulls.
 
Height 10-14 feet. Spacing 24 inches.
 
Sowing Sunflower seeds:
 
Sow seeds outdoors after the last frost date, 1 inch deep. Full sun.
 
Grown by Megan's Heirloom Seeds.