The montanas, alpinas, and macropetalas, along with a few other types of clematis, are the clematis that fall into pruning class 1. The LFHs are the ones that fall into pruning class 2 and that is the group that HF Young falls into. The viticellas, the native US species, and a variety of other clematis fall into pruning group 3.

In spite of all this classification, clematis don't read the articles that put them into the classification groups and to be quite honest, other than the differences between which specific cultivars are put into groups I and II, both these groups are generally ones that bloom on older wood that can be produced on last year's growth/or on wood produced during the current year's growth cycle and are generally pruned after blooming to control size or remove deadwood. They can also be pruned in late winter to remove deadwood.

All that being said, most of the type IIs can be pruned in late winter and still have blooms later in the spring than if they are not pruned. In the warmer zones, the type IIs can also get rather ratty looking by midsummer. Pruning them back then and keeping them watered well during the heat of the summer will normally give rise to a second flush in the late summer or early fall. My HF Young has always been pruned back in the early winter and given me the original flush of blooms by mid spring and then pruned back in midsummer to give me a second flush of blooms almost as big as the initial spring flush in late summer/early fall.

Thank you, that info is very helpful.