Views: 52 Author: ICEVER-Nancy Publish Time: 2025-10-09 Origin: ICEVER
This article explores whether ordinary light bulbs can effectively support plant growth.
It first explains how plants use light, emphasizing the importance of specific wavelengths in the photosynthesis process. Next, it examines different types of light bulbs that can help plants grow, including LED, fluorescent, and specialized grow lights, comparing their efficiency and light spectrum.
Finally, the article discusses the differences between a regular light bulb and a grow light, focusing on light quality, intensity, and energy efficiency.
Overall, it concludes that while normal bulbs can provide some light, they are generally not ideal for healthy and sustained plant growth compared to purpose-designed grow lights.
The basic principles of plant light requirements
Plants convert light energy into chemical energy through photosynthesis, driving growth and metabolism. Photosynthesis primarily occurs in chloroplasts, where chlorophyll a, chlorophyll b, and carotenoids absorb light energy.
Specifically:
Blue light (400–500 nm) promotes leaf unfolding and stem thickening;
Red light (600–700 nm) promotes photosynthesis and flower bud differentiation;
Green light (500–600 nm) penetrates the leaves, assisting in deeper photosynthesis.
Plants absorb light energy most efficiently in the blue and red light regions, which is the scientific basis for optimizing the red-blue light ratio in plant growth lights.
Light Intensity
The rate of photosynthesis increases with increasing light intensity, but tends to plateau or even decrease after exceeding the light saturation point.
Insufficient light intensity leads to excessive vegetative growth and weak leaves; excessive light intensity may cause photoinhibition or leaf scorch.
Light Quality
Different wavelengths of light have different effects on plant morphology and photosynthetic efficiency.
The red-blue light ratio significantly affects plant architecture, flower bud differentiation, and biosynthetic products.
Photoperiod
Short-day, long-day, and neutral plants are sensitive to day-night length.
Photoperiod regulates flower bud differentiation, bolting time, and plant physiological rhythms.
Key spectrum requirements for cannabis at different growth stages
Types and spectral characteristics of general lighting lamps. Comparison of common lamp types and spectrum adaptation
| Light type | Spectral characteristics | Applicable stage | illustrate |
Fluorescent lamps (CFL / T5) | Blue light, weak red light | Seedling stage / cutting stage | Gentle enough to not hurt the seedlings, but the energy is not enough to support the flowering period |
Metal Halide Lamp (MH) | High proportion of blue light | Growth period | Promotes compact leaves and strong stems, suitable for the vegetative growth stage |
High-pressure sodium lamps (HPS) | Rich in red light and less in blue light | Flowering/fruiting period | Promotes flower bud formation and fruit development, often used with MH |
Red and blue LED lights (Red + Blue LED) Red and blue LED lights (Red + Blue LED) | The spectrum is concentrated in the red and blue regions | Growing season to flowering season | High photosynthetic efficiency, but visually glaring and unnatural |
Full Spectrum LED Lights (Full Spectrum LED) Full Spectrum LED Lights (Full Spectrum LED) | Covers 400–700 nm (simulating sunlight) | Full cycle | One lamp can be used for multiple purposes, from seedling cultivation to flowering |
Quantum Board LED (Quantum Board) | High PPFD, smooth spectrum | Full Cycle (Professional Grade) | High energy efficiency, good uniformity, suitable for professional planting tents |
COB LED Light (Chip-on-Board) | Wide spectrum + high brightness concentration | Growing season + flowering season | Suitable for large plants or high-demand stages |
Schematic summary of the "Spectral adaptability" of each light
Light type | Seedling stage | Growth period | Flowering period | Full cycle adaptability |
Fluorescent lamps (CFL/T5) | ✅ | |||
Metal Halide Lamp (MH) | ✅ | |||
High-pressure sodium lamps (HPS) | ✅ | |||
Red and blue LEDs | ✅ | ✅ | ||
Full-spectrum LED | ✅ | ✅ | ✅ | |
Quantum Board LED | ✅ | ✅ | ✅ | |
COB LED | ✅ | ✅ |
Energy consumption and heat generation characteristics of different types of common lamps：
Regular lights are created to provide light in a dark space.They are compose of narrow spectral wavelengths and normally there is no proper spectrum of light to engage photosynthesis.That said incandescent bulbs can actually be used to grow seedlings but once you start to get larger plants the bulbs simply do not produce enough wattage/energy for the plants to do photosynthesis.
Grow lights are lights that specialize in producing lighting in the 400nm-700nm light range while producing a high wattage.(wattage is the energy that plants can use to convert amino acids into sucrose and other important compounds they use to grow.
While some plants might scrape by under regular light bulbs, their yield would likely be meager. On the flip side, grow lights such as LED grow lights and HPS grow lights significantly boost plant growth, thanks to their tailored light wavelengths.
We strongly advise against attempting to nurture sun-loving plants under standard light bulbs– they'd likely wither in such unsuitable conditions.
