Growing Fennel in Zone 4B

Fennel is a beautiful, aromatic herb with a mild licorice flavor. Both bulb and herb types are worth growing.

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 — fennel doesn’t transplant well
• Bulb fennel needs cool weather to form; herb fennel is more heat-tolerant
• Keep consistently moist for best bulb development
• Self-seeds prolifically if allowed to flower
• Attracts swallowtail butterflies — their caterpillars love it

Companion Planting

Good companions: dill (same family, attracts same beneficials)

Avoid planting near: most vegetables — fennel is somewhat allelopathic (inhibits nearby plants). Grow separately.

Harvest Timeline

Bulb: 65-90 days from seed; herb leaves anytime

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.