Flowers my chicks won't eat?

I have 2 free range bantams in my back garden (we think 2 girls but thats a whole new topic!) and they are eating everything!

There is a lawn of grass, its a bit mossy but there is grass too, the have a feeder full of corn and hen layer pellets, they get goodies like apple, bread, cake and the left over parrot food (sunflowers, millet, nuts, seeds etc) but the little rascals have nibbled most of my flowers, lavender, aqualigia, tulips, primrose, oh they oved all the primula and have started on the strawberry plants and the rhodedendrons (spelling?)

Tomorrow I was thinking of making some covers to give the new growth a chance to recover using chicken wire, I wanted to ask if any one lse had the same issue? what helped? do you know of any nice flowers they wont eat?

I dont want to stick them in a run as they are used to the whole garden to scratch around.

Let me know your thoughts please