12/12 cycle from the start, what would happen?

A friend of mine has recently told me he want's to start growing some plants, the guy who he's getting his information from has told him you need to have the lights on 12 hours then off 12 hours, i told him he's probably miss heard him as the 12 hour light cycle is for when you want the plant to flower but he checked again and he's certain his 'experienced grower' friend has told him always make sure you use a 12/12 light cycle.

So my question is, what would happen if someone tried to grow this way? Would you just end up with really poor plants or would they not even flower?

ahhh, i to remember my first grow....good times. well to answer ur question 12/12 is ONLY FOR FLOWERING. althoug u can technically put a plant into flowering at any point u want during growth. Most growers use 24/0, 20/4, and the most common 18/6.These are known as vegetative light cycles, where the plant will not flower but instead focus on growing leaves and brances. When ur plant has reached the desired maturity or the desired height you kill off male plants, if any, and place ur girls in to 12/12. In 8 weeks your plants will have double/tripled in size during the flowering phase.Also to answer your question,I have never tried growing from seed to flower using only 12/12, i dont think the results would be good seeing as a plant builds genetic material as it matures, this genetic material has alot to do with THC levles...A little chart i follow for a basic grow is: Veg=4wks Flwr=8wks...3 months, smoke, enjoy!

U can do it like that, the only thing that sufferrs is the yield.
Pending on the strain and type of light, u should see around a half oz per plant, mabe maore maybe less.
Flowering them for even 2 weeks will dramatically increase yield.
I'm doing a bunch of bagseed, and I want smoke asap, so I am doing mine 12/12 from seed. They are 2.5 weeks old and just now females are showing, no males confirmed yet tho.
I wouldn't do it this way normally but I need the grow space for mother plants in 6 weeks.

Read this:
International Cannagraphic Magazine Forums - 12/12 From Seed: A Different Way To Grow