We have plants in our chicken play area but have had to fence them off with poultry wire domes and such. We just bend the wire into the shape we want, wire pieces together etc. and set it around whatever we don't want eaten. The reason being that everything they can get to will be toast including stuff they should not be eating. We even had them peck through the trunks of bananna trees in their run.
It's not as nice looking as leaving the plant unprotected but it's better than having no plants.
It's not as nice looking as leaving the plant unprotected but it's better than having no plants.