I have a rather very protected backyard and the most hardy and reliable variety has been Berberis thunbergii Atropurpurea, it generally comes through winter with little damage compared to other varieties I grow. The dwarf 'Concorde' is not a hedging type, rather a very attractive border accent plant that has rarely sustained any dieback due to being under a deep blanket of snow. But, I would not recommend barberry for an exposed location and those that do not receive reliable snowcover.

I wouldn't go with barberry, personally. I'm in 2b, but I can barely get it to overwinter, let alone be tip hardy. Cotoneaster might need some trimming. I don't have any Korean lilac, but that might be nice.

My favorite out of those picks is the ninebark, I have lots of them in my yard and they are very hardy. They are quite slow to leaf out in spring, though.

I would never use barberry as a hedge, whether it's hardy or not. When I was in my last house in zone 5, I had a Rose Glow Barberry hedge... OK, so it was very pretty, but it was dangerously thorny! Also, it was popping up in different places too. Since that time, I would never use barberry again, as a hedge or as a specimen plant.

Maybe Caragana? They are fast growing and very hardy, tall and bushy with upright growth habit. Some pest issues I think but maybe something to look into. :)

Ginny

Ginny, I have caragana hedges already, lots around this part of the country, my biggest gripe about them is how large they get. The bees like them. Ostrich, are you saying they sucker or is it from seed. I guess it really doesn't matter, thorny things growing where you don't want them would not be nice. Thanks all. I am leaning towards Korean lilac or maybe hardy roses but would have some pruning with them.

I would probably go with dwarf lilac. Cotoneaster needs pruning and ninebark is really nice but in my yard it isn't a dense shrub at all. I think it's better as a specimen than a hedge.

Oh, also you could consider a larger spirea like bridal wreath. Or evergreens such as globe cedars (if you don't have deer!) or mugo pine. The only thing I don't like about mugo pine is how the snow knocks it flat.

Yes there is deer, some years worse than others. I would like a cedar hedge but would have to fence the whole yard. One winter they ate the Virginia Creeper to the ground, usually they don't touch it.