Tympanic Membrane perforation following blast injury.

This is a case of blast injury and this patient has been following for last 4 weeks. Margins of the perforation are healing slowly. Clot has retracted. Stapedius tendon, Round window and Incudostapedial joint is clearly visible.

Question: How long do you wait for these perforation to heal before taking up for surgery?
(I Plan to wait for at least 3 months)