Today, we will gain understanding about the photoperiod in a cannabis plant’s life cycle as they grow and develop. As we know, cannabis plant is annual and, in order to guarantee its proper growth outdoors, we must provide some particular care. To succeed, we have to clearly identify these phases to avoid failure and better control the growth of the plant.
During this first stage, the seed comes to life when these basic conditions exist: humidity, temperature and air.
When combined, this series of elements makes the seed pop, breaking its coat and giving birth to the seedling. Thus, we will see an emerging small radicle that pushes the cotyledon and the seed coat out of the soil. These are the moments in which the sprouted seed will feed on the cotyledon energy until the first leaves start performing the photosynthesis.
The required conditions for a seed to germinate are a temperature between 18 and 23 ° C and a humidity of 80%.
In this initial life cycle, after the output of the cotyledon leaves, the first “true” leaves will grow with a distinct single ridged blade, followed by a second set of three. The leaves will progressively develop more rounded points: 5, 7, 9 and even 11 in some cases. Once our plant has reached this level, we also know it has already developed a proper primary root system.
In the course of this vegetative stage, plant growth takes off until it acquires an appropriate structure, firm enough to support the weight of the future flowers that will develop in a third phase. It is now when leaves growth is at its highest, stem and branches grow thicker and the plant produces new leaves rapidly.
The switch starts in spring (for outdoors) when the days are longer. During this period, our cannabis plants will exclusively focus on growing, so we recommend not neglecting the care and feeding of your crop, since this moment will be fundamental to assure the proper formation of the plant stem and leaves. With proper care, plants will grow stronger and sturdier, keeping you away from eventual issues in the next stage. In order to guarantee this, ideal temperatures are between 18 and 24 ° C with humidity between 70 and 80%.
This phase starts when daylight hours shorten (by June 21 in Madrid, as reference) and the duration of nights is longer. However, depending on the plant strain and its genetics, some variants will bloom before others.
In this period, plants will reveal their gender and will double in size, or even triple in the case of some sativas. Internodes spacing tightens to form a structure that will sustain the emerging flowers. The ideal temperature to promote these changes is between 18 to 24 °C and 50-60% humidity.
Two weeks after the change of daylight hours, plant growth slows down and the first flowers appear. Once the process of flowering begins, the plant will put their energy into producing buds. At this time, mature leaves (the largest ones) start losing color and turning yellow, the plant gains weight and generates resin and aromas (so-called terpenes). At this time, we recommend pruning of the low growing branches and all small internal buds since these will not thrive but only take out part of the plant energy, preventing the production of large buds.
After several weeks in this phase, and always depending on the genetics that we are growing, the final stretch begins. Flowering usually lasts between 7-10 weeks in the case of Indicas, and from 12 to 16 weeks for Sativas.
As the flowering progresses, we will observe how pistils in the nodal areas adopt a brownish color due to oxidation. Besides, leaves continue to lose color gradually (this is because the plant feeds on the reserves that are left) while the plant focuses on the buds formation, by compacting its flowers. When you notice there are changes in the structure of the plant and its aromas, this will be the indicator to start with root washing technique.
After several washes (up to 3), the plant will lose most of its yellowish leaves, revealing dense and firm buds full of aroma. In the same way, the calyxes curl and close, tightening the brownish pistils. Depending on each grower taste, you will find trichomes on the cut point, deep in the flower (personally, I prefer doing it once trichomes turn amber). Now, we can consider that the flowering and maturity cycles are both completed and it is time to harvest, by cutting off our flowers.
Warning: if your plant has been pollinated by a male outdoors, you will find seeds in your flowers.
I do hope this article is helpful to optimize your crop and maximize your yield!