Growing Sunflowers in Zone 4B

Sunflowers are easy, dramatic, and multi-purpose — they attract pollinators, provide seeds, and make great cut flowers.

Zone 4B has a short growing season — start seeds indoors when possible and use season-extending techniques like cold frames and row covers.

Top Growing Tips

• Direct sow after last frost — they grow fast and don’t need a head start
• Tall varieties need wind protection or staking
• Plant in succession for weeks of blooming
• Branching varieties produce many smaller flowers instead of one big head
• Leave seed heads for birds in fall or harvest for roasting

Companion Planting

Good companions: cucumbers, corn, beans, lettuce (shade from tall varieties)

Avoid planting near: potatoes (may inhibit growth), pole beans (compete for light)

Harvest Timeline

Flowering in 55-75 days; seeds ready when back of head turns brown

About Zone 4B

USDA Hardiness Zone 4B has an average last spring frost around May 1 and first fall frost around Oct 1. All planting dates above are calculated from these frost dates. Your specific location may vary — check with your local extension office for the most accurate dates.