I just had to deal with a problem, and know it is one of biggest problems for growers doing it for the first(FEW) times. It is all really pretty simple. Any strain that flowers late into the year,SATIVAS,SKUNKS and many HYBRIDS, my general rule of thumb is when you start them indoors (from seed), do so no earlier than around the first of March. Let them grow in vegetative lighting(18-24hrs a day of light) until the first of April, then move them outside. Because they flower when their is usually less than 12hrs of light, they will have enough light not to flower and stay in a vegetative growth stage. The reverse is true for early flowering strains(KUSHES,some INDICAS, and HYBRIDS). I start my seedlings for these at the beginning of April, and move them outdoors by the middle to end of April. By this time there will be enough hours of daylight to keep them from flowering, unless you put them in a shady spot, which if you do, can force them to flower, then it's on you! As far as clones are concerned, the exact same method is true. Of course you can set up[ lights in your outdoor Garden to keep this from happening, and leave them on a few hours after Sunset, or put them on a few hours before Sunrise. But this can and is a problem if certain dire circumstances occur, like heavy rain, or neighbors wondering why your Backyard is lit up like an Airport runway at certain times of the dark. Anyways, since I have had to explain to so many people how to do this correctly, I thought I should post this thread and maybe help someone out. SINCERELY, JAMESTHEGREEN.