It would be a difficult choice, but if I had to select one deciduous tree for my garden, it would have to be the Korean form of Stewartia pseudocamellia, and this is why: here is a small tree (25-30′) with striking interest in all 4 seasons. In winter, a mature Stewartia pseudocamellia var koreana shows off its handsome narrow pyramidal shape, which broadens a bit with age, and lovely exfoliating bark, exposing shades of tan, pink and gray. In spring, it breaks anew with fresh dark green elliptical leaves, arranged alternately along its branches. In early summer, lovely 3″ white camellia like flowers are displayed. Each blossom only lasts a short time, but there are so many produced over several weeks that you never feel it is not performing. In autumn, Stewartia pseudocamellia is truly mesmerizing, flashing you with foliage in shades of brilliant red, orange, gold and green.
Stewartia pseudocamellia is native to Japan and Korea, and the Korean form is generally considered a bit hardier. The Korean form tends to have a more narrow pyramidal shape than the species found in Japan. In its native habitat, it is found growing with Clethra barbinervis and Enkianthus campanulatus, both exceptional large shrubs or small trees, with multi season interest. Stewartia pseudacamellia var. koreana grows best in sun or partial shade in a humus rich but well drained soil, out of strong wind. It is hardy to minus 20F and grows well in zones 5-8.