Growing Kohlrabi in Zone 4B

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 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

• 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 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.