Exposing germinated cannabis seeds to light is a crucial step in the growing process. Understanding the ideal time to start lighting your seedlings can make a significant difference to their health and subsequent growth. This article explores the best practices and timings for effectively lighting your young cannabis plants.
The crucial role of light in cannabis germination
Light plays a major role from the beginning of a cannabis plant’s life. After germination, when the first set of leaves (cotyledons) appear, the young seedlings need light to initiate photosynthesis. Light is therefore essential not only for growth, but also for the structured development of the plant, allowing it to adequately absorb the essential nutrients present in the soil.
The first days after germination
In the days following germination, it is best to place the seeds under a source of soft, indirect light. This practice helps avoid the stress that too intense light could cause on the delicate seedlings. Specific plant lamps offer a wide range of suitable light spectrums, from blue light promoting initial growth to red light useful during flowering.
Choosing the appropriate light source
When it comes to selecting a light source for your cannabis seedlings, there are several options available. Each has its specific advantages depending on the different growth phases of the plant.
Compact fluorescent lamps (CFL)
THE CFL are often recommended for the early stages of seedling life due to their low intensity and low heat production. They mimic natural light well and are an economical yet effective option for encouraging healthy growth without burning young plants.
LED panels for cultivation
LED technologies are becoming increasingly popular in cannabis cultivation, notably thanks to their energy efficiency and their ability to diffuse a more controlled light spectrum. The use of LED is ideal for maintaining a constant temperature around the seedlings while offering an adjustable spectrum that accompanies the plant from germination to maturity.
Planning the light exposure
The intensity and duration of light exposure must be carefully planned to optimize the growth of the plant without endangering it.
Seedling lighting schedule
Cannabis seedlings generally benefit from a light cycle reflecting the long days of summer. A common cycle consists of 18 hours of light followed by 6 hours of darkness. This diet encourages active, robust growth by simulating the optimal conditions of the natural growing season.
- Installing your lights : Keep light sources close to the seedlings (20-40cm above) to maximize exposure without risking burns.
- Frequent adjustments : Adjust the height of the lamps as your plants grow to maintain the necessary light intensity, without exposing the seedlings to excessive heat.
- Measure responses : Carefully observe the reactions of your seedlings and adjust settings if you notice signs of stress such as chlorosis (yellowing of leaves).
Common Troubleshooting Light Problems
It is possible that despite your best efforts, problems relating to light exposure may arise. Here’s how to fix it effectively.
Stretched and weak plants
seedlings which stretch abnormally are often a sign of a lack of light. In response, make sure the light source is close enough to the plants or consider increasing the wattage of the bulbs or extending the daily exposure time.
Burns and stress from light
Conversely, bleached or burned leaves indicate excessive exposure. In this case, reduce the light intensity or move the lamps away from the plants to avoid heat trauma. The romance of the exact light requirement varies between species and each individual situation requires personalized adaptation.
