Alie if you live in a state where you can do so you should grow GRAPES, rasberries and blue berries.. You and your turtles will appreciate it in the summer time and have tastey treats not to mention they will cover your fence. I'm all about growing things I can use or eat along with serving a purpose.
You can also grow sunflowers in the summer time and corn both will grow tall and cover the fence area... of course just for summer but they are pretty and you can eat both. Also guavas you can plant inside or outside of the fence.. they are a bushy plant that will both cover the fence, or inside give your turtles a place to hide and the fruit is YUMMY. They never loose their leaves so it will always be a cover for the fence and in return you and the turtles will of course have another tastey treat. There are different types of guavas, pineapple, strawberry. You can shape them into whatever type you want if you want them bushy or tree like... pretty little good plants