How to grow outdoors in Caribbean?

What organoman said about shinning a light on it when it gets dark will work. If you was going to do autoflower then you will need a spot where they get 12 hours of sunlight constantly, otherwise they won't yield a decent smoke. If you got a spot in mind why don't you try a photoperiod and an autoflower. That way next time you have a idea of what's going to be best for you.

You can easily interrupt their night cycle when in vegetative growth by shining a light/torch on them for a minute or two each evening about an hour or two after sunset. This will interfere with their 12 hours of darkness and prevent them from flowering too early. I would stick with photoperiod plants, autoflowers are quite useless outdoors, even more so with only 12 hours of light, they really need 18 hours of light to produce any sort of meaningful yields. Growing Sativas with a 20-30% infusion of Indica genes will give you plants that yield really well, will still have a strong Sativa type of high, but will flower more decisively than pure Sativas that can linger in flower for 12-16 weeks or more. Amnesia Haze from Sweet Seeds is very productive and with a nice Sativa head high. Ace Seeds have some awesome Sativa and Sativa dominant strains that are well stabilised genetically and very pure land race types that are at the pinnacle of refinement, if you are after authentic "real" cannabis that will blow your socks off. Highly recommended for cannaseurs! Another breeder with exceptional strains are Mandala Seeds, these too will impress with their quality, genetics and ease of cultivation. Hope this helps, Organoman.

You could veg indoors under a light for a few weeks (or as long as you want really) and then take ot outside to flower. Or plant several autos cause they dont give a damn about light schedules but 12/12 they dont really max out so plant a few.