If a garden is small there is no room for large wide shrubs, so the gardener is often forced to search for skinny varieties.
Narrow shrubs are referred to as columnar in shape, as they form narrow living columns in the garden. There is an attractive tall columnar boxwood, Buxus sempervirens ‘Graham Blandy', that is evergreen so it is attractive in all seasons of the year. It slowly grows to 10-12 feet but stays only 2 feet wide in zones 6 through 8. It does well in hedges and also as an accent and can be used to punctuate formal gardens.
Japanese holly ‘Sky Pencil' is another good narrow evergreen shrub. I used to have three in my garden and loved the columns as well as their name. They were robust for years but I recently lost one for reasons unknown, so now I only have a pair instead of a trio.
To console myself I bought a deciduous Fern Leaf Buckthorn for another part of the garden, and it is handsome as well as deer resistant. Its botanical name is Rhamnus fragula ‘Ron Williams', and it has lacy foliage, which adds texture to the landscape. It grows just 5-7 feet tall and 2-3 feet wide in zones 2-7. It prefers well-drained soil but is adaptable. Just give it a little slow release fertilizer each spring. I like it as a backdrop for brightly colored flowers, and it can be used either as a specimen or as a narrow hedge.