No problem... any time.

Just veg until the plant is about a foot high with at least 7 - 10 nodes and then go 12/12.

The size of the plants all depends on the light you are using though... My LED gets the plant a foot high and very bushy in about 4- 5 weeks.

Someone using a less powerful light will have to veg for longer.

You can see my current grow in the link in my signature, click on LED Grow no. 2 with Rhino Seeds....

Glad I could help. At least now you will begin to get your crops rotating much quicker and the plants will be shorter so you can have more plants.

I grow 4 plants in a 90cm x 90cm space. If you have a good light and 1m2 you can do the same. Just follow my second grow and you should be fine

Take Care

S.L.