Buck roses are generally shrubs. If you enter a show where the shrubs are further broken down, they go in Modern Shrubs. It sounds like in the current show they would go in the climber/shrub group. If you give us names, we can be more specific.

You really have to look them up. Newer ones tend to be Modern Shrubs, but older ones are sometimes Grandifloras. If there is an Open HT/GT class, it's an excellent place to put them. They tend to open too fast to do well in Exhibition HT/GT, but because of that often look very fresh and appealing in the Open class.

I would think that the fairs, even if they are not ARS sanctioned, would still go by the classifications published in the ARS handbook?
Lee