Growing Kohlrabi in Zone 3B

Kohlrabi is the underrated brassica of the spring garden. It grows fast, tastes like a mild broccoli stem crossed with an apple, and is ready in 45-60 days.

Zone 3B has a short growing season — start seeds indoors when possible and use season-extending techniques like cold frames and row covers.

Top Growing Tips

• Start indoors 4 weeks before last frost or direct sow 4 weeks before
• Harvest when the swollen stem (not a root — it grows above ground) is golf-ball to tennis-ball size
• Larger than 3 inches means it’s getting woody and tough
• Tolerates light frost; plant early for spring harvest and again in late summer for fall
• Thin to 5-6 inches apart for proper bulb development

Companion Planting

Good companions: beets, onions, cucumbers, aromatic herbs

Avoid planting near: tomatoes, pole beans, strawberries

Harvest Timeline

45-60 days from transplant; harvest when 2-3 inches in diameter

About Zone 3B

USDA Hardiness Zone 3B has an average last spring frost around May 15 and first fall frost around Sep 15. 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.