During the second week of the flowering stage in marijuana plants, significant developmental changes occur. This phase marks the transition from vegetative growth to the flowering stage, where the main focus of the plant shifts towards reproduction. The plant begins to form buds, which are the reproductive organs. These buds will eventually develop into the flowers that contain the cannabinoids such as THC and CBD, for which the plant is cultivated. The plant's energy is now primarily directed towards bud formation, with a decrease in the growth of new leaves or height.
The plant also undergoes hormonal changes during this week. There's an increase in the production of ethylene, a hormone that promotes flowering. Photoperiod-sensitive strains respond to the reduced daylight hours (or artificial light hours in indoor growing), which triggers the flowering process. Additionally, the plant's nutrient requirements change; it requires more phosphorus and potassium to support bud development, and less nitrogen than in the vegetative stage. The plant's overall metabolism increases to support these developmental changes, necessitating careful attention to watering and feeding schedules by the grower.