Is kohlrabi a perennial plant?
Written by
Julia Anderson
Reviewed by
Prof. Martin Thorne, Ph.D.Kohlrabi functions on a biological timeline of two years, yet it rarely exceeds the first year of plant life. I have a Kossak Hybrid left in my Zone 6 garden for the winter. In the spring, it bolted flowers but developed inedible, woody bulbs. This biennial will fulfill its life cycle under natural conditions, but farmers usually harvest them before frost desiccating the plant.
Year One Priorities
- Energy focus: Bulb and leaf development
- Harvest window: 50-80 days after planting
- Frost tolerance: Survives 25°F (-4°C) briefly
Year Two Realities
- Energy focus: Flower and seed production
- Bulb quality: Tough and fibrous
- Seed viability: 3-4 years if properly stored
Overwintering necessitates precise parameters. Mulch thoroughly with 12 inches of straw before the ground freezing. I have had about 30 percent success overwintering plants during Maryland winters, while protected plants simply rot with freezing and thawing conditions. The use of cold frames is said to improve overwintering rates; however, they require that you attend to them weekly (ventilate) to prevent fungal growth.
Soil Preparation
- Drainage: Mix sand into planting beds
- pH balance: Maintain 6.5-7.0
- Mulch after first hard frost
Spring Care
- Remove mulch gradually as temps rise
- Apply balanced 10-10-10 fertilizer
- Watch for bolting signs
Many gardeners replant every year for good-quality bulbs, so choose fast maturing varieties like Early White Vienna, for spring and fall crops. I succession-plant every 14 days until midsummer, providing tender bulbs without relying on an overwintered crop. Store seeds in a cool and dry place for four years of viability.
Read the full article: How to Grow Kohlrabi: Complete Beginner's Guide
