Plant Sunflowers in Zone 5b
Seed-starting, transplant & harvest dates for USDA Zone 5b
Direct sow
May 2
Harvest (~80d)
Jul 21
In Zone 5b, the average last spring frost is around April. Sunflowers is a half-hardy crop, so sow it directly around the dates above.
Last spring frost
Apr 25
First fall frost
Oct 8
Growing season
166 days
Full Sunflowers grow guide → · All crops for Zone 5b →
Frequently asked questions
When should I start sunflowers in Zone 5b?
Direct sow outdoors around May 2.
Can I direct sow sunflowers in Zone 5b?
Yes, direct sow around May 2.