He's going through a bad/difficult/rough 'patch' [='spell'] right now.
The chair's original paint is still visible 'in patches'. [=in spots]
The doctor 'patched' him 'up', so he's going to be as good as new.
(..) What's goin' on? What is it? What is it? Will somebody please tell me what's goin' on? Mr Radley shot at a prowler out in his collard patch. A prowler? Oh, Maudie! Whoever it was won't be back anytime soon. Mr Radley must have scared them out oftheir wits. (..)1962 To Kill a Mockingbird