I have a question about a phrasal verb put off.

As far as I know after this phrasal verb following a -ing verb. For example: I put off washing dishes.
Today I have written a message where I wanted to use this phrasal verb, but I couldn't.
The sentence was: Don't put off phoning me, when you come. I'm absolutely not sure whether is correct or not.

Is my comma correct? Does it sound natural?
Can you render it if it doesn't sound natural

Thank in advance.
Boris from cold Moscow.