I've been growing for longer than I care to remember and this is the first time I have heard that seedlings can be put on 12/12 and they will continue growing and once they are sexually mature they will automatically start to flower ?

Do I understand you correctly canuck ? O.K., so lets say I put week-old seedlings into 12/12. How long (on average) will they continue veg. growing before they are sexually mature and start to flower ? OR does the flowering response commence immediately once under 12/12 ?