Can i flower my 12" tall plant whenever i want?

Of course; that would be the main benefit of growing indoors--we are allowed to manipulate light cycles, as well as many other variables, for the well being of our plants. The flowering light cycle is 12 hours on/12 hours off.

Oh, and for future reference, 12" is the height that I, and a number of other growers flower plants at.

~Lycanthropy

Edit: One important thing to remember about flowering is that the plants will continue to grow vertically for 2-3 weeks after changing the light cycle to 12/12. Some plants, depending on a number of variables, will double or even triple in size. A normal finishing height after flowering at 12" under a 250w HPS is about 18-22".

 

might wanna switch ur plants to 18-6 or sumthin like that 24 hour growth isnt exactly healthy..... your plant has no rest time..... its almost harsh on the plant it needs resting time..... id give it a few days with a lessoned light schedule.... peace out sam

 

Well, then again it may be too late, as he may want to have a smaller profile for flowering. If not, I would definitely change to 18/6 for the sake of the plants; I only use 24/0 for seedlings/clones for the first 1-2 weeks.

Doing this will also reduce the shock to your plants when the light cycle suddenly changes to 12/12 like it never would in nature.

~Lycanthropy

 

And the argument is still goin' on!
18/6 or 24/0 ? Do the plants need a rest period while vegging because it is constantly photosynthesising producing more vegetation? No one can agree but 1 thing is for sure, same plants under 24/0 or 18/6 in the same circumstances....the ones under 24/0 will grow 25% faster since they are photosynthesising 25% more.
"info taken from European Cannabis Cultivation" <-- Good Read!
CWL

 

If you flower early, it causes stress and could turn it into a hermpahordite. There is a 70% chance of this. You want to wait until small sexual development for pre-flowering.

 

Most indoor growers flower earlier than in nature and I seriously doubt 70% go herm because of it. I rarely saw herms when growing indoors and I usually flowered seedlings at a foot tall regardless of there age. I did notice however ,that if you start a plant under 24/0 and switch it to 18/6 at 6 inches, they will usually show sex before they reach a ft. This keeps you from wasting space in your flowering room with males. Not all strains will do this, sativas in particular usually take longer to show sex than an indica.

 

If u switch to 12/12 before preflowering it slows the start of the flowering process!
It would be quicker to wait for pre-flowers and then switch to 12/12!
It definitely stresses the plant cos its not mature enough yet to flower and is forced into doing so,
But if ure stuck for height etc then wot can u do lol
CWL