Good looking garden, dude. Making me jealous I only have 3 plants. Wouldn't mind gettin' my hands on that Jamaican strain. Love sativas. 
EDIT: From what I understand, upward curl can be due to rapid growth or trying to expel excess moisture. There can be other reasons, though, and I'm not really experienced in identifying the different curls. Sorry I can't be of much help.

EDIT: From what I understand, upward curl can be due to rapid growth or trying to expel excess moisture. There can be other reasons, though, and I'm not really experienced in identifying the different curls. Sorry I can't be of much help.