Light & Light Cycles
Lighting
Lighting is the use of artificial or natural light to power plant growth, providing the energy cannabis plants need to develop properly.
Why Lighting Is Critical in Cannabis Cultivation
In cannabis cultivation, lighting refers to the light sources used to drive photosynthesis (the process by which plants convert light into energy). Light quality, intensity, duration, and placement all directly affect plant growth, structure, potency, and yield. Proper lighting is one of the most critical factors in successful cannabis cultivation.
How Lighting Evolved in Cannabis Growing
Historically, cannabis was grown outdoors under natural sunlight for thousands of years. Indoor cultivation expanded in the late 20th century, leading to the development of specialized horticultural lighting systems. Early indoor growers used fluorescent and high-intensity discharge (HID) lamps, while modern cultivation increasingly relies on advanced LED (light-emitting diode) technology for efficiency and control.
How Light Spectrum Drives Plant Growth
Lighting works by delivering photosynthetically active radiation (PAR), which is the portion of light plants use for growth. Blue wavelengths encourage vegetative growth and compact structure, while red wavelengths support flowering and bud development. Full-spectrum lights combine these ranges to mimic sunlight across growth stages.
How Lighting Schedules Control Growth Stages
In cannabis cultivation, lighting schedules are used to control plant life cycles. During the vegetative stage, plants typically receive 18–24 hours of light per day. Flowering is triggered by reducing light to 12 hours on and 12 hours off, simulating seasonal changes. Consistent light cycles are essential to prevent stress or unwanted hermaphroditism.
Choosing the Right Lighting Type and Intensity
Lighting type and intensity must match grow size and plant needs. LEDs offer energy efficiency, lower heat output, and customizable spectrums. HID lights produce strong intensity but generate more heat and require additional cooling. Poor lighting can lead to stretching, weak branches, low yields, or reduced cannabinoid production.
Common Lighting Problems and How to Fix Them
Common challenges include uneven light distribution, excessive heat, and incorrect light distance. Solutions include proper fixture placement, reflective surfaces, and monitoring light intensity.
Related terms:
Photosynthesis, PAR, Vegetative Stage, Flowering Stage, and Cannabis Cultivation.
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