Light cycles are crucial for cannabis growth because they control the plant’s vegetative and flowering stages. Cannabis is a photoperiodic plant, meaning it relies on specific light and dark periods to determine its growth phase. Here’s why light cycles matter:
1. Vegetative Stage (18/6 or 24/0 Light Cycle)
- Light Duration: 18-24 hours of light, 6-0 hours of darkness.
- Purpose: Encourages fast vegetative growth, allowing the plant to develop strong roots, stems, and leaves.
- Best for: Young plants and mother plants (if cloning).
💡 Tip: Some growers use 24 hours of light, but 18/6 is more natural and saves energy while still ensuring strong growth.
2. Flowering Stage (12/12 Light Cycle)
- Light Duration: 12 hours of light, 12 hours of uninterrupted darkness.
- Purpose: Triggers flowering in photoperiod strains, leading to bud development.
- Best for: Once plants reach the desired size and structure.
🌿 Critical Note: Even minor light leaks during the dark period can stress plants and cause hermaphroditism (creating unwanted seeds).
3. Autoflowers (Independent of Light Cycle)
- Autoflowering strains do not depend on light cycles to flower.
- Common cycle: 18/6 or even 20/4 throughout their life.
- Advantage: Simpler growth process, as they flower based on age, not light.
Light Intensity & Spectrum Matter Too
- Veg Stage: Blue spectrum (400-500nm) promotes leafy growth.
- Flower Stage: Red spectrum (620-700nm) encourages bud production.
Getting the light cycle right ensures maximum yield and potency while avoiding issues like stress and poor development.
