Sexing

Sexing cannabis is the process of determining a plant's biological sex — a critical task for growers using regular (non-feminized) seed because males produce no smokable flower and will pollinate any nearby females, ruining the crop with seeded buds. Sexing is performed by inspecting pre-flowers at the internodes during late vegetative growth (week 4-6) using a 10x loupe, jeweler's magnifier, or smartphone macro lens. Female plants display teardrop-shaped calyxes with two white V-shaped pistils emerging from the tip; male plants display round pollen sacs on short stalks resembling tiny grapes or balls. Sexing techniques: (1) Standard pre-flower inspection — examine internodes during late veg, looking for the diagnostic structures; (2) 12/12 from seed — flipping to flowering immediately forces sex expression within 7-14 days; (3) Cloning + flipping — take a clone from each numbered seedling, flip the clones to 12/12 to identify sex while keeping the mother plant in veg, then keep only the females; (4) DNA testing — labs like Phylos and Medicinal Genomics offer leaf-tissue sex tests with results in 2-3 weeks. With feminized seeds, sexing is only required as a hermaphrodite check, since 99%+ of plants will be female. Outdoor growers in legal regions face additional risk: airborne pollen from neighboring male plants can travel miles, fertilizing entire fields of females within hours. This is why feminized seeds dominate the modern market — they eliminate the entire sexing workflow and the risk of accidental pollination.