Flowering Stage
The reproductive phase of the cannabis plant when buds form, driven by light cycle changes and culminating in harvest.
Flowering is the part of cannabis cultivation everyone obsesses over because it's when the actual smokeable product develops. The basics are well understood: shorter days trigger it outdoors, a 12/12 light schedule triggers it indoors, and it takes roughly 7-11 weeks depending on cultivar. A lot of online grow advice about exact nutrient ratios, defoliation timing, and 'tricks' to boost yield is folklore dressed up as science. The plant biology is real; most of the optimization theater isn't.
Definition
The flowering stage is the period in the cannabis life cycle when the plant shifts from vegetative growth (leaves and stems) to producing reproductive structures — the resinous inflorescences commonly called buds or flower. In photoperiod-sensitive cultivars, the transition is triggered by a sustained dark period of roughly 12 hours, which suppresses the phytochrome-mediated signal that keeps the plant in vegetative mode Strong evidence[1][2]. Outdoors this happens as days shorten after the summer solstice; indoors growers force it by switching lights to a 12-on / 12-off schedule.
What happens chemically
During flowering, glandular trichomes on the bracts proliferate and produce the cannabinoids (THCA, CBDA, CBGA and others) and terpenes that define the cultivar's chemistry Strong evidence[3][4]. Cannabinoid content generally rises through flowering and peaks late, though the exact trajectory varies by chemotype. Terpene profiles also shift over the cycle, which is one reason harvest timing is treated as a craft decision rather than a fixed date Weak / limited[4].
What it does
Flowering is when the smokeable, vapable, or extractable product is actually made. Yield, potency, and aroma are largely determined here, alongside genetics. Environmental factors with solid evidence for affecting flower quality include light intensity (within plant tolerance), temperature, humidity (low humidity late in flower reduces botrytis risk), and nutrient availability Strong evidence[2][5].
What it doesn't do
Flowering does not magically respond to most of the folklore advice circulating in grow forums. Claims that specific defoliation schedules, 'flushing' with plain water in the last two weeks, or playing music for plants meaningfully improve cannabinoid content are not supported by controlled evidence Anecdote. A 2021 study on pre-harvest flushing, for example, found no significant differences in yield, potency, or smoke quality between flushed and unflushed plants Weak / limited[6].
Used in articles about
This term appears in articles on Vegetative Stage, Autoflowering Cannabis, Trichomes, Harvest Timing, and Photoperiod.
Sources
- Peer-reviewed Moher, M., Jones, M., & Zheng, Y. (2021). Photoperiodic response of in vitro Cannabis sativa plants. HortScience, 56(1), 108-113.
- Peer-reviewed Chandra, S., Lata, H., ElSohly, M. A., Walker, L. A., & Potter, D. (2017). Cannabis cultivation: methodological issues for obtaining medical-grade product. Epilepsy & Behavior, 70, 302-312.
- Peer-reviewed Livingston, S. J., Quilichini, T. D., Booth, J. K., et al. (2020). Cannabis glandular trichomes alter morphology and metabolite content during flower maturation. The Plant Journal, 101(1), 37-56.
- Peer-reviewed Aizpurua-Olaizola, O., Soydaner, U., Öztürk, E., et al. (2016). Evolution of the cannabinoid and terpene content during the growth of Cannabis sativa plants from different chemotypes. Journal of Natural Products, 79(2), 324-331.
- Peer-reviewed Rodriguez-Morrison, V., Llewellyn, D., & Zheng, Y. (2021). Cannabis yield, potency, and leaf photosynthesis respond differently to increasing light levels in an indoor environment. Frontiers in Plant Science, 12, 646020.
- Peer-reviewed Stenerson, K. K., & Oden, G. (2021). The impact of flushing on cannabinoid and terpene levels in cannabis flower. RxLeaf / industry-reported analytical study summarized in Cannabis Science and Technology, 4(4).
How this page was made
Generation history
Drafting assistance and fact-check automation are used, with a human operator spot-checking on a weekly basis. See how articles are made.