Can kale grow indoors year-round?
Written by
Tina Carter
Reviewed by
Prof. Martin Thorne, Ph.D.Kale is grown indoors requires strict light and spacing management. I've been cultivating the Dwarf Blue Curled under 6500K LED panels for 14 hours a day, harvesting approximately 1.5 lbs every 8 weeks per plant. It is essential to maintain a temperature of 60-70°F (16-21°C); I utilize a small heater as necessary to avoid bitterness commonly associated with cold.
Light Requirements
- LED grow lights: 30-40 watts/sq ft at 12-18 inches height
- 6500K spectrum mimics summer sun for vegetative growth
- Timer-controlled cycles prevent overexposure
Hydroponic Systems
- Kratky method: Low-maintenance, no pumps required
- Nutrient solution: 800-1200 ppm nitrogen focus
- pH 5.8-6.2 prevents nutrient lockout
Temperature Control
- Day: 65-70°F (18-21°C)
- Night: 55-60°F (13-16°C)
- Humidity: 40-50% to deter mildew
Pest prevention is easier to manage inside. I quarantine new plants for 2 weeks before spraying neem oil every two weeks. Sticky traps catch fungus gnats, which are often a nuisance in hydroponics. I also employ oscillating fans for airflow to strengthen stems and disrupt the breeding cycles of pests.
Harvesting methods can impact the time that they last. Simply snip the outer leaves off at 6-8 inches while leaving 5 inner leaves for continued growth, and this is how to achieve that. My kitchen system generally produces 10 oz of greens every week, which is enough for salads and/or smoothies. Remember to keep rotating the plants under the lights every three days to allow for even growing.
Stay clear of common errors like overcrowding plants together. Try spacing your plants 12" apart, as my first attempt failed due to shaded leaves touching the ground. I used 5-gallon/12-liter buckets for my soil, or you can grow in 3-gallon/8-liter reservoirs for hydroponics. Test your EC on the water weekly; if the salts are very high, that's an indicator of nutrient burn.
Read the full article: How to Grow Kale: Complete Planting and Harvesting Guide
