when do you start counting down when flowering, when you start 12/12 or when you first notice white hairs?
Agreed^^ As soon as it shows sex it officially starts its flowering cycle. The reason for this is because Cannabis produces the hormone that starts budding and flowering its entire life, or at least from seedling it begins to make it with chlorophyll and such. This chemical is useless when sunlight is on the plant for more than half a day. Now, the natural light cycles of early spring have longer and longer days, and this goes on into the summer giving the plant ample time to be in Vegetative stage. When fall comes around the days get shorter which in turn allows the hormones that are responsible for budding it collect and after a couple weeks the plant has enough of the hormone to bud, the its in its budding stage. If you 12/12 a smaller young cannabis plant before its ready it tends to shoot up with growth and show sex mad early.....what else can i say on the subject.... o, alot of time when you leave a Cannabis plant in Vegetative for long periods of time, more than it would naturally be in it shows sex . I think its because it accumulated enough of the hormone so it just buds out. Hope I helped someone!