There is a chipmunk that is in the yard that continues to live in my large outside potted plants. How can I get rid of him?

I hear you can spray some castor oil around the plants, but I am not sure if it will hurt the plant or not.

If you just wish him to go away, I would recommend a natural repellant such as paprika or chili powder. If those don't work the next step up would be the products designed for burrowing animals like Mole-stop which contain eugenol and eucalyptus oil; they stink but won't harm the plants.

Trapping and relocating the little bugger would be the more expensive but more certain alternative.

I have tried about everything and my only success has been Trap and relocate. It may be a process if your neighbors are not willing to help keep them under control as well.

Menards and Home Depot sell a solar powered device that looks like a large thumb tack. You stick it in the ground and it vibrates the soil every 30 seconds. Drives the little guys nuts so they leave for your neighbors house, $19