Lawn Tractor tires

[Tollster]

Anyone know of the cheapest place t find lawn tractor tire for my Wheel Horse 18 horse hydro? I think they are the sam size as the 20 horsepower tractor they had for years.
Mine are dry rotted after 17 years.

 

[Ledgemere Farm]

Northern sells them, but I don't know if they are the cheapest. Try Wal MArt?