Does kohlrabi require full sunlight?
Written by
Julia Anderson
Reviewed by
Prof. Martin Thorne, Ph.D.Kohlrabi is a vegetable that grows best with 6 or more hours of daily direct light. In my garden, the south-facing beds produced fist-sized bulbs after 55 days. The kohlrabi under shade never grew larger than golf balls. Another lesson learned the first summer growing kohlrabi is that in hot zones, placing kohlrabi with morning sun and afternoon shade helps prevent bolting.
Ideal Light Conditions
- 6-hour minimum for bulb expansion
- Morning light enhances photosynthesis efficiency
- Use shade cloth (30%) above 85°F
Low-Light Adaptations
- Grow compact varieties like Grand Duke
- Reflective mulch boosts light by 20%
- Rotate containers daily for even exposure
Lack of light is evident by tall, skinny stems without a lot of bulb development. In my balcony plant trials, I used lighting for 4 hours a day, which gave me thin plants. Once I moved these plants to a spot where they would get more sunlight, the plants grew back in about 10 days. You can also use mirrors, white building walls, or viewed sunlight to reflect on previously shaded beds.
Reflective Solutions
- Aluminum foil around plants
- White-painted growing boxes
- Mylar sheets on north garden borders
Container Tactics
- Mobile raised beds on casters
- Rotate pots 90° daily
- Elevate containers on light stands
Kohlrabi's ideal environment is full sun; however, urban gardeners often get by with a few hours of sun each day with good planning. I have received credible kohlrabi crops growing under apple trees. The key was timing and planting the kohlrabi when the apple trees dropped their leaves. The strategy is to pair kohlrabi with other herbs that tolerate shade, such as mint, in the limited sun.
Read the full article: How to Grow Kohlrabi: Complete Beginner's Guide
