Number of plants

How many plants can be legally grown with a medical card in the state of California?

Statewide it's 6 mature(budding) and 12 immature, though it can vary by county.

redding cal. is still 6 plants mature. 12 babies.

How long till a baby is a mature? Is it when it buds or a certian week?

I don't know to what degree law enforcement chooses to split this particular hair, but I believe a plant is considered mature once it starts budding.