Give them (or your other birds) a separate feeder at another location in your yard. Put an apple, ut in half in the feeder you want the Mockingbird to use to entice him over. Maybe some mealworms too. Let me know if this helps
NC NATIVE PLANT LISTS--Downloadable
Mecklenburg County created an extensive list of native plants, their soil and light requirements and what they provide for wildlife. Feel free to download these files to your computer Native Tree List.xls