Germination up to seedling
U can tell when its no longer a seedling bcuz of its size.
During the vegetative stage u will notice the plant getting taller and new foilage will develop..the roots will dig deeper causing the root ball to get larger/bulkier. The plant will remain in the vegetative stage until u decide to change the lightung schedule giving it less hours or light....thats how u know when ur vegging.
once u do that u will have transisted into the flowering stage of growth.
During the flowering stage u will first notice one of two things:
1. little white hairs (female plants)
2. little grape shaped pollin sacks(male plants)
In ur garden u only want the female plants, so if u see any grape shaped pollin sacks on your plants, pull that plant from the ground, get it outta your garden bcuz u ONLY want females. Now that u only have females U will notice buds produced on the plant during the flowering stage..thats how u will know ur flowering
wait until 50% of the white hairs turn colors and then harvest.
for a more in depth description do a lil research and then try to better word ur question
from what i understand...
since u control the lighting, u determine which stage of growth its in.