Growing 6 plants in one pot

[twoguysupnorth]

too funny, farting in a hot tub full of friends. its not a great idea, but ive done it as well(4 plants in a pot, not farting) i ended up with a male and cut it out with no problems, but stinky is right again. a single plant in a pot produces the same or more than 3 in a pot. live and learn.

[stinkyattic]

You need to transplant a couple times to optimize use of light and soil space.
Smaller pots can be crowded under a light to make a continuous canopy and not lose light to the soil surface. For those of us who veg under flouros, it's important to be able to move the pots to keep within that 2" sweet spot undert he tube.
Another reason is the way that a plant grows its roots. They will pretty much continue to spread until the pot is full... if the pot is too big for the plant, it can be seen as a waste of energy. If you plant a seed in a big pot and don't transplant, the plant will STILL become rootbound.
Personally, I transplant at least twice- 3" to 4" to 12" and flower right after the final transplant. I've also done an intermediate repot into 1 gallon pots before the 12", and transplant DURING flower (not as bad for the plant as you might think). The way it's timed, the roots are starting to tangle around the inside corners of the pot and it makes transplanting really easy, having that dense root ball to hold the soil together.