American Honda has been out of the riding equipment market for 15 years now, and has no plans to return.
I think they probably evaluated the ZTR market, but it got awfully crowded very quickly. There are some ZTR units that have Honda V-twin engines, but I'm not aware of any other brands of lawn tractors or rear-engine riders that use Honda engines.
Honda Europe still makes garden tractors (13-24hp) which are made in Italy, with engines imported from Honda's engine plant in Thailand.
