Ohio Rev. Code Ann. § 2321.21

When, with reasonable diligence, the grounds for a new trial could not be discovered before but are discovered after the term at which the journal entry of a final order, judgment, or decree has been approved by the trial court in writing and filed with the clerk of the court for journalization, the application for a new trial may be by petition, filed not later than the second term after the discovery, nor more than one year after the final order, judgment, or decree was rendered, on which a summons must issue, be returnable, and be served, or publication made, as in other cases.