What is the best way to prevent tires from dry rotting if they are going to be sitting?

You can let you car sit a year and you shouldn't have to worry about them dry rotting.

I used to have a show car,for 3 years we parked the car in the snow bank and the tires still looked new after 3 years

One thing not very well known is that the worse enemy of tour tires is ozone. When i used to be a professional motrcycle racer they used to tell us all the time not to store tires near a furnace or anything fired with a spark because the starter makes ozone which makes for premature deterioration of tire rubber.

I would grab some jackstands and let the car rest on the framerails instead of on the wheels. Then you can store your tires inside or somewhere safe. Its always good to let the car rest on the frame, esp a heavy one.

armor all, and lots of it.. it work on my 84 but it was only sitting for about 7 months..

get them off the ground