Ohio Rev. Code § 3767.09
When a nuisance is found to exist in any proceeding under sections 3767.01 to 3767.11, inclusive, of the Revised Code, and the owner or agent of such place whereon the same has been found to exist was not a party to such proceeding, and did not appear therein, the tax of three hundred dollars, imposed under section 3767.08 of the Revised Code, shall, nevertheless, be imposed against the persons served or appearing and against the property as set forth in this section. Before such tax is enforced against such property, the owner or agent thereof shall have appeared therein or shall be served with summons therein, and existing laws, regarding the service of process, shall apply to service in proceedings under sections 3761.01 to 3767.11, inclusive, of the Revised Code. The person in whose name the real estate affected by the action stands on the books of the county auditor for purposes of taxation is presumed to be the owner thereof, and in case of unknown persons having or claiming any ownership, right, title, or interest in property affected by the action, such may be made parties to the action by designating them in the petition as "all other persons unknown claiming any ownership, right, title, or interest in the property affected by the action." Service thereon may be had by publication in the manner prescribed in sections 2703.14 to 2703.19, inclusive, of the Revised Code. Any person having or claiming such ownership, right, title, or interest, and any owner or agent in behalf of himself and such owner may make defense thereto and have trial of his rights in the premises by the court; and if said cause has already proceeded to trial or to findings and judgment, the court shall, by order, fix the time and place of such further trial and shall modify, add to, or confirm such findings and judgment. Other parties to said action shall not be affected thereby.
R.C. §3767.09