When should i switch from veg to flower?

I have one plant that is approx 4 weeks old and stands
About 6-7" with several fan leaves and nodes at every
Spot a leaf meets the stem. At what point should I switch to 12 and 12?

Is that 4 weeks from seed? What size area are you growing in? Id let it get about 12" then switchin

4-6 weeks or 12" is the standard I would say (pending on a few variables - i.e. grow space size, etc).

lil nugs , switch to 12/12 when ever u want to, keep in mind it will double or so in size. i went 12/12 from seed on my current grow and there 3ft tall and still growing taller as they bud

It depends on your grow space and your lighting.

This is a question that is so hard to answer because ther are so many differant ways to do a grow.But i will give it my best shot if you have a growroom with a 4ft in height then i would say flower at 1 and 1/2 ft because plants no matter what the strain unless dwarf will strech a little.But ha slong has the light is kept close to the tops then the nodes will be kept close and a far better end product will be the result.Also it all depends on how many you are wanting to do at any time if you are doing just say 2 under 1 600 and height is not a issue then let those babys get big flower at around 2 1/2 ft this will give you a plant around 5/6ft but only do this if you have the height but more important the light to maintain such a big plant.If you are doing a few then i would flower at a ft i always have done in the past and the plants will throw you around 4/5 ounce per plant under a 600 hps 4 plants.Hope all go well in the upcomeing grow stay green peace TYKE

Thanks for the advise everyone. My plant is in a 3 gallon pot under one cfl light.
It was a clone I bought from the club so I'm guessing its roughly 4 weeks old.