BackHow to maximise the pigmentation of cannabis for an explosive colour

The cannabis market is undergoing a fascinating evolution towards varieties that offer a complete sensory experience, in which visual impact plays an important role in the purchase decision of growers, going beyond the traditional parameters of taste, potency, and yielding capacity. Cannabis plants that develop intense purple, violet, pink, or bluish hues not only provide aesthetic satisfaction but are also associated with premium genetics and refined growing processes, elevating the status of the final product.

 

The influence of American genetics has been particularly noticeable in this chromatic revolution. Varieties such as Zkittlez, Gelato, Purple Haze, or Wedding Cake have set new standards in terms of colour expression, combining sweet flavours with an impressive resin count and THC levels above 25%. This combination of factors has created a market where colour has become an indicator of quality and exclusivity. But far from being merely decorative, this visual phenomenon responds to complex biochemical processes that can be enhanced with specific growing techniques, turning each crop into a true work of natural art.

 

To understand how to maximise the pigmentation in cannabis plants, it is essential to learn the biochemical mechanisms that produce these spectacular colours. And anthocyanins are the group of pigments responsible for these vibrant hues that we see in many plants, including cannabis. These flavonoid compounds function as water-soluble pigments that are stored in plant cells, especially when the production of chlorophyll (the main pigment responsible for photosynthesis) decreases. And they not only provide colour but also perform important protective functions, acting as natural antioxidants that protect the plant from oxidative stress or damage caused by UV radiation. The concentration and distribution of anthocyanins determines not only the colour intensity but also its uniformity throughout the plant. This may include flowers, leaves, and stems, leading to a truly impressive visual spectacle that sets these varieties apart from conventional genetics.

 

 

The synthesis of anthocyanins responds to various environmental and genetic factors, following a specific pattern that is usually intensified during the final stages of flowering or when the plants experience some controlled stress. Therefore, this natural process can be enhanced by manipulating the environmental conditions to help the plants express their maximum chromatic potential.

 

Temperature is the most influential factor in the production of anthocyanins. During the flowering phase, it is essential to implement a thermal regime that favours the synthesis of these pigments without compromising the overall health of the plant. Reducing night temperatures to about 10 - 15°C during the last 3 - 4 weeks of flowering is the most effective technique. This thermal decline mimics the natural conditions of autumn, activating the genetic mechanisms responsible for colouration. However, it is crucial to maintain daytime temperatures within the appropriate range (20 - 24°C) to preserve the normal metabolism of the plant.

 

The pH of the growing medium also has a direct influence on the chromatic expression of plants. In acidic (low pH) conditions, anthocyanins tend to exhibit red tones, whereas they become bluer in alkaline (high pH) conditions. A neutral pH promotes purple shades. To enhance these colours, it is recommended to maintain the pH slightly below the general optimum range (between 6.0 - 6.3 in the substrate), as this favours the absorption of certain micronutrients which are essential for the synthesis of anthocyanins.

 

Nutrition during the flowering phase requires specific adjustments that prioritise the availability of phosphorus and potassium whilst gradually reducing the supply of nitrogen. This nutritional change not only promotes the flowering but also induces controlled stress that stimulates pigment production. For instance, one of the most effective techniques is to slightly reduce the availability of phosphorus during the final phase of the flowering, as this stimulates the plant to produce more anthocyanins in response to stress, resulting in more intense purple and red tones.

 

Just as light influences the activity of chlorophyll, it can also stimulate the expression of secondary pigments in cannabis. Small amounts of certain UV wavelengths, particularly UV-A, can help activate protective responses in plants, one of which involves the production of pigments. Moreover, the gradual reduction of light intensity during the last few weeks of flowering can stimulate the production of anthocyanins as a natural protective mechanism. Some growers experiment with periods of extended darkness before harvest (48 - 72 hours) to maximise the final pigmentation.

 

In addition to thermal, light, and nutritional stress, other techniques can also enhance the pigmentation without significantly compromising the plant’s yielding capacity. Mild water stress during the last few weeks, or selective pruning of large leaves to increase light penetration, are complementary strategies that can be equally effective.

 

It is essential to distinguish between two main types of pigmentation in cannabis: genetic colouration and ripening-induced colouration. This differentiation is crucial for understanding realistic expectations and appropriate techniques for each type of plant. Genetic colouration is manifested in varieties specifically selected for their natural ability to produce anthocyanin pigments. These plants, such as Purple Haze and Purple Kush, carry genes that are coded for enhanced anthocyanin synthesis under appropriate conditions. In these varieties, colour may appear even under normal environmental conditions, although it may intensify considerably in controlled stress situations. By contrast, ripening-induced colouration is a natural process that occurs in virtually all cannabis strains during the final stages of their life cycle. This phenomenon, which is similar to the colour change in leaves in autumn, results from the degradation of chlorophyll and the compensatory synthesis of other pigments ─ and, although visually appealing, it doesn’t necessarily imply that there’s special genetics involved in the pigmentation.

 

 

We have recently added some outstanding varieties to our Linda Seeds catalogue. These genetics are the epitome of cutting-edge cannabis with spectacular colours, each offering unique features that make them ideal options for growers looking to maximise the visual impact of their grows. These include:

 

 

Remember that the key to success lies in patience, careful observation, and the gradual implementation of controlled stress techniques that help these plants to express their maximum chromatic potential without compromising their overall health. With the right varieties and techniques, every grower can achieve those explosive colours that transform an ordinary grow into an extraordinary visual experience.