overwatering and maybe a bit of nuteburn from your soil is whats causing it. 65f is perfectly fine dude(in fact its about ideal....), outside temps get alot colder during fall at night than that. round here in oct/nov it gets to be about 40-50 degrees at night and my outside plants dont seem to care, they can survive short periods of under 32f if need be, the thing thats the problem is frost, and even then it can still take a few milder frosts w/no problems before the first severe(hard frost) frost kills it and lol, their is a chance they could survive that even. lol