Hedge Cotoneaster (Cotoneaster lucidus)

Cold hardy shrub often planted as a formal hedge. Grows 6 to 10 feet tall with a dense upright habit. Leaves are glossy dark green and turn shades of red and orange in fall. In spring it bears small pink to white flowers followed by black berries that persist into winter and are eaten by birds. Tolerant of pruning and shaping which makes it suitable for trimmed hedges or natural screens. Adaptable to many soil types and low maintenance once established.

While usually it's used for hedges, an interesting use case is Cotoneaster as a pear rootstock, it can in fact be grafted with pear cultivars, and is known to be a long lived dwarfing pear rootstock, a combination popularized in Russia. 

Hardiness: Zone 2 to 3