With the recent legalization of cannabis, more and more cannabis growers are emerging. Whether it is cannabis or other plants, light is essential for plants. If you want plants to have high quality and yield, you must conduct an in-depth analysis of their needs for light.
In the world of plants, light is like food for plants. Different plants have different needs for this "food", especially specialty crops like cannabis and the vegetables we eat every day. Some plants may prefer a "big meal" (stronger light), while others may be content with a "snack" (weaker light). By understanding the "taste" of plants, we can better care for them and help them thrive.
The concept of photosynthetically active radiation (PPFD)
To comprehend the light requirements of plants, we first need to understand what photosynthetically active radiation (PPFD) is. Although the term may seem complex, it essentially acts as a ruler that measures the "portion of sunlight useful to plants." PPFD indicates the number of photons per square meter that reach plant leaves, which are crucial for photosynthesis. Just as different people have varying dietary needs, plants also have different PPFD requirements at various stages of their growth.
Cannabis’s need for light：
Germination Stage: This stage requires a mild PPFD to support healthy seedling growth.
Growth period: As the plant matures, cannabis's demand for light increases, and the PPFD value is usually 800 μmol/m²/s.
Flowering stage: This is the stage with the highest light demand in the cannabis life cycle. This stage has the highest PPFD demand, which can reach 1100-1600 μmol/m²/s. During this period, intense light contributes to flower formation and development, which in turn affects final yield and quality.
Vegetables’ light needs：
The light requirements of vegetables vary depending on their type (leaf vegetables or fruit vegetables) and growth stage. In particular, there are obvious differences in the requirements for photosynthetically active radiation (PPFD).
Light requirements of leafy vegetables
Leafy vegetables, such as lettuce, spinach, and kale, generally have lower light requirements throughout their growth stages. Their PPFD needs typically range from 150-250 μmol/m²/s. This level of light is sufficient to support their photosynthesis and promote chlorophyll formation, helping the leaves grow large and green. While leafy vegetables thrive in lower light conditions, insufficient light can lead to slower growth and paler leaf color.
Light requirements of fruits and vegetables
Fruiting vegetables, such as tomatoes, peppers, and cucumbers, generally have higher light requirements. Their PPFD needs during the general growth stage are usually above 250 μmol/m²/s. These plants require more light to support flower formation and fruit development. Higher light intensity aids in increasing sugar accumulation in the fruit, thereby enhancing its flavor and nutritional value. Insufficient light can lead to stunted fruit development and reduced yields.
The importance of light to plants is self-evident. Although natural light is currently a crucial source for plant growth, it is influenced by seasonal changes, weather conditions, and geographical location, making it challenging to precisely control the PPFD levels. This is why sometimes, despite your careful attention, the yield and quality of your plants may be significantly reduced.
Compared to natural light, artificial light sources like LED grow lights can precisely control PPFD (photosynthetically active radiation) to ensure plants receive the necessary light intensity for optimal growth. After a decade of in-depth research, the TheOneGrow team has focused on the specific needs of cannabis cultivation and LED technology. They have designed specialized LED grow lights tailored for cannabis to maximize its growth potential. You can click on the dialog box below to learn more ~
Note: The above content is reproduced from VANQ