Despite your grammar, I think I deciphered what you are trying to ask... You can flower them whenever you want, it all just depends on how much yield you want to pull down. 1.5ft in veg will translate to about a 3ft finished plant, depending on the strain and the technique/style used to grow. There is a technique called Sea of Green or SOG that you don't even veg the plants. Once they have started roots from clones, they go directly into flower. Your plants don't get much over 1.5ft tall, but you keep this on a perpetual cycle so that you can harvest every two weeks. Hit the link in my Sig and you can kind see the different stages of growth under my CFL's. I am doing a variation of the SOG.