when should i switch to flower

so my plant is about 12 inches right now, and due to space restrictions the max height it can reach is 34 inches. should i switch it to flowering right now or wait til its gets to 20 inches?

Since some varieties triple in height during flowering, flower now to minimize the chance of running out of room. Better safe than sorry.

flower NEOW! some strains can triple in size during the stretch, so be careful

last week probably

12/12 now and u still might have to tiethe branches down