4 bonsai to be worried about

[JaBoiBrodie]

I have 4 bonsai, a gensing ficus, salix boydii, pusch Norway spruce, and a cotoneaster. I live in a USDA zone 6b. Should I be worried about the winter months with the 3 outside trees or will they survive the winter. I live in Erie, PA amd our winters are usually HELL. I could also keep them garage kept in the winter.
Also are there any bonsai specifically for usda 6b other than variations of pines?

 

[JaBoiBrodie]

Edit: I also saw a map that says I'm in hardy zone 4 being against lake erie. I'm going to say zone 6b though because it doesn't get below -5°F often in winter

 

[Treefer]

I am150 miles south of you in zone 6b. With the lake-effect weather patterns up your way, I would consider you to be a full zone colder, 5b. Consequently, I would protect everything but the spruce. Maybe someone near you, or even in Buffalo, NY, can provide better input.

 

[ABCarve]

I’m in Girard, just down the road. I’m 6 miles south of the lake which is a zone colder than on the lake. It depends on a few factors. Is your garage heated or attached to your home. I keep mine in my unheated garage but it’s attached so the walls around it moderate the temp to a point where I need to open the door slightly. I try to keep them below 40 and above 26. A friend in our study group lives on the lake, buries his in the ground with success. There are other Bnutters here that live in relatively cold places that mulch them in on the ground but are protected somehow. Some species can take more cold than others. I don’t have any of those species you referred to so don’t have any firsthand knowledge. The spruce is very cold hardy.