Welllllllll.... their nutritional needs may vary day by day. First, they shouldn't get layer feed unless they are laying (or just about to lay). Second, what are you gonna do when it rains and you are throwing feed onto a wet surface? Third, have you calculated how much a chicken needs each day for its age? Fourth, how are you going to ensure ONLY your hens are eating the feed, and not visiting sparrows, crows, jays, finches and other wild birds? Fifth, that's a pretty wasteful method of feeding chickens.
Really, you should use a feeder, and probably keep it in the coop, so ONLY the chickens get to it. That would also guarantee your birds establish the coop as their home, where they eat The Good Stuff.
Just my opinion, for what it's worth.