Plant Sunflowers in Zone 3a
Seed-starting, transplant & harvest dates for USDA Zone 3a
Direct sow
May 22
Harvest (~80d)
Aug 10
In Zone 3a, the average last spring frost is around May. Sunflowers is a half-hardy crop, so sow it directly around the dates above.
Last spring frost
May 15
First fall frost
Sep 15
Growing season
123 days
Full Sunflowers grow guide → · All crops for Zone 3a →
Frequently asked questions
When should I start sunflowers in Zone 3a?
Direct sow outdoors around May 22.
Can I direct sow sunflowers in Zone 3a?
Yes, direct sow around May 22.