The line between whether a plant is a "tree" or a "shrub" is sometimes very thin and quite blurry! We use the following criteria to decide which type applies to a certain plant:
Cephalotaxus harringtonia 'Fastigiata'
Cryptomeria japonica 'Araucarioides'
Cryptomeria japonica 'Champagne'
Cryptomeria japonica 'Spiralis', Japanese Cedar
Cunninghamia lanceolata 'Glauca'
Fagus grandifolia, American Beech
Sequoia sempervirens 'Atlanta'