help!

plants are about a month and a half into flowering and all of a sudden the fan leaves are beggining to yellow and fall off. the buds still grow out of the node where the leaf used to be, but i dont know if this is bad! what is the cause of this!?

get some pics and post it, but it sounds like a nute issue.

theyre outdoors and i havent used nutes once, they were just a sort of experiment but the buds are pretty developed, is it an issue just to let the big leaves die if the buds keep growing?

Plants need food as well as light and water; you are seeing the symptoms of an advanced nitrogen deficiency.
This would not have happened had you been feeding all along; however, it's late in the year to do anything about it except keep it from getting worse.
Give a bloom fert at this stage.