I guess I don't hold much for a pretty yard, but I do want it manageable. My chickens are mini lawnmowers. If I don't have grass, so much the better. Actually I pasture them where and when I think I need to. I had them in the garden a few months and they just got put in with the goat, so I can grow a winter garden and some winter grass for them to eat on later, just before I plant a spring/summer garden and then so on. I use them for what they can do for me. It takes them a little while to clean up for me, but they are very through about it. They will also be healthier if I keep moving them about and they will improve the soil. I know its gets so very hot here in the deep summer and the last thing I will want to do in August will be go outside and clean the garden, which will have pretty much have died, but the chickens will love the bugs, grass, weeds, and vegetable plants and will be more than happy to clean up for me.
I used to plant flowers, but I am more interested in vegetables and fruits now. If I would plant flowers again, I think I would stick with things that the chickens didn't like. There are a few in the lily family that you could probably get away with. The trick would be to have them well established, before your chickens got to them. Probably roses also, provided they are trained to grow high up....I would think they might be interested in the leaves and flowers that would be lower. My chickens and ducks actually kept my lilies free of weeds and grass and would use the space as cover for protection by day and I would find eggs hidden in the beds also. They didn't eat the lilies at all. Mine were a wild type that grows wild in my area that I transplanted and a few St. Josephs also and some Iris'.....also a wild type, but very pretty purple and yellow color.
I think the chickens can actually be of a benefit to you, provided you have a good game plan and use them for what they are good for. I am a nurse and I use the nursing process in all aspects of my life and the nursing process is "as easy as a pie" (A P I E )
A........Assessment: What is the problem?
P........Planning: How can I fix it?
I........Implementation: execute a plan.
E.......Evaluation: Did it work? (if it didn't, you start over)