Introduction – Understanding Light Spectrum
To understand the complex nature of the color spectrum of natural light, we need a prism. This allows us to see the various colors which make up natural light. When the light is refracted you can see its base collection of colors.
Recent scientific studies have taught us that plants actually make varying decisions based upon the spectrum of light which they are exposed to. This means that a different color spectrum could have an effect on anything, ranging from germination growth and even the bud formation on a cannabis plant.
Previously growers had no control over which spectrum of light they exposed their cannabis plants to as it was only really possible to grow your plans outdoors. Increases in technology mean that we are now able to grow just as well, if not better, in a contained environment. Being able to buy your own lights and create a color spectrum which you believe will benefit your cannabis plant is a huge plus point for indoor grow operations.
The Role of Light in Cannabis Growth
Cannabis growth undergoes several stages, each with unique light requirements:
- Germination and Seedling: Young plants require gentle light, often provided by blue wavelengths.
- Vegetative Stage: Cannabis plants need more intense light, with blue wavelengths encouraging healthy leaf growth.
- Flowering Stage: Red wavelengths play a crucial role, signaling the plant to begin bud formation.
Color Spectrum Options for Cannabis Cultivation
- Blue Light (400-500 nm): Essential during the vegetative growth phase, blue light promotes strong stems and healthy foliage. It’s crucial for developing a plant structure capable of supporting future buds.
- Red Light (620-750 nm): This spectrum becomes critical during the flowering stage, where it encourages cannabis plants to produce buds. Red light simulates the longer wavelengths of autumn light, indicating to the plant that it’s time to reproduce.
- Full Spectrum: Mimicking natural sunlight, full-spectrum lighting supports the plant through all its life stages. It combines various wavelengths to provide a balanced light source that promotes overall plant health and development.
Choosing the Right Light for Your Cannabis
Its hard to give a definitive answer when it comes to saying which color spectrum is the best for growing cannabis. This is because each differing spectrum gives its own benefits and it comes down to depending on what you are looking for as a grower.
The two main color spectrum’s we will be looking at are blue light and red light, these two spectrum’s can be found in many affordable commercial grow lights. Grow lights with a high ratio of blue light are perfect for the vegetative state as they will allow your cannabis plant to grow short and wide, with large healthy leaves.
Red light on the other hand is more suited for the flowering stage, this particular color spectrum will encourage your cannabis plant to grow tall and will also promote budding.
The Suns Changing Light Spectrum
We can look to mother nature for the perfect example of the way plants use color to detect what is going on around them. During summer the plant will be exposed to more blue light due to the suns position in the sky, the plant will process this information and then grow short and squat in order to maximize the amount of sunlight it is receiving in order to increase growth.
However as summer comes to an end, the plant will be exposed to more red light causing it to grow longer stems, these longer stems will leave the plant in a good position to start budding and pollinate via the wind.
Our Recommendation
In our opinion the best solution is to use a grow light with a higher ratio of blue light during the vegetative stage to enable your plant to make the most of its initial growth phase. When your cannabis plant begins flowering you should switch to a grow light with a higher ratio of red light in order to maximize its budding potential.
However not every one uses this method, some growers may prefer to grow under a red light for the whole grow as it means their cannabis plants will have longer stems, meaning they are easier to train during the vegetative stage. On the other hand growers with height restrictions will opt for a blue light from seed to harvest in order to ensure that their plant does not grow too tall for their grow room.
Conclusion
The size of the effect caused by a different color spectrum varies from strain to strain, the effect can also be mitigated by other factors such as insufficient light. For example if you exposed your cannabis plant to a weak light with a higher ratio of blue light then the stems may still grow long as the plant will be left reaching for light.
On the flip side a very powerful grow light with a high ratio of yellow light will result in a short plant as the plant will already be getting a sufficient amount of blue light from the powerful light source.
This leads me to the conclusion that the amount of light is key, you can use whatever spectrum you like as long as you ensure you are using a reputable, powerful grow light which will ensure your plant receives all the light it needs to reach its full potential.
