I have been told that if growing from seed they need 8wks veg to be mature enuf to flower properly,is this correct and is time to start flowering from clones different???
Talking about clones, which I use almost exclusively.
Different types:
Sativas - These usually triple in height when you flower them
Indicas - Grow some more during flower, usually under 2 or 3 feet final
Hybrids - These are crosses of different genetics. Often they are for high yield.
Most clones will show pre-flower right away as they are the same age as the mothers (mature). The reason you take so much time with seeds, is that you would like them to develop pre-flowers, before you put them to flower which takes awhile.
My examples:
Bubba Kush (indica) - flowered at 18 inches - finished at 28 inches
Blue Dream (hybrid) - flowered at 24 inches - finished at 6 feet
*alternate method - flowered at 9 inches - finished at 30 inches
So depending on your strain, your light and the height available to grow, you would start flowering at your desired height.
Just my $ 0.02