When my day olds are in the brooder house , I chop clover and grass and throw handfuls to them . They are curious and will try anything. I have taken clumps of sprouted wheatgrass and thrown that to them and they eat it and then scratch the root mass apart. When they are two weeks old they go into moveable pens. They peck at everything at least once. They love the legumes , plantain , and grass - especially with seed heads. When they are older and are free ranged they eat those plants all day. They remain curious and will eat alot of green matter - but they don't bother my garden plants except for tearing up mulch and scratching young plants up by the root - they prefer to eat those pasture plants.I used to mix alfalfa and clover into the babies feed but found that throwing handfuls onto the bedding will teach them better. Also when I have bought ready to lay pullets which came from a run or pen they took right to grazing , being curuious and they steered right to those same plants the experienced hens ate - clover , plantain , and grass. Are you keeping the birds penned in one area , can you free range or create moveable pens or paddocks? If so their instinct will assume control . If you have to keep them in runs - I always wanted to try the " Lady Balfour " method . Creating three or four runs that are rotated from the same coop , season one you use the run 1 as mulch layer and
compost pile - throw grass clippings , leaves , straw ,and kitchen scraps onto ground and let chickens scratch around for a season. Season 2 move chicken to run 2 and grow garden crops in run 1 for 2 seasons. At least the birds will eat some vegie scraps and have plenty of insects.