Zelkova serrata

The Zelkova serrata, also known as Elm or Japanese Zelkova, is an Asian cousin of our native elms that has many advantages: majestic, this large deciduous tree is recognised by its short and stocky trunk covered with a beautiful bark speckled with ochre, and topped with a broad, rounded and airy crown that will take on fiery tones in autumn. Like its parent, the Zelkovia carpinifolia, it is an excellent alternative to the elm, to which it bears a resemblance because it is insensitive to Dutch elm disease that decimated many of these trees in the 1970s. Its accommodating nature allows it to thrive in all deep soils without excessive limestone. This species can withstand temperatures as low as -40°C (1°F).

Native to northern and eastern Asia (Japan, Korea, Taiwan), Zelkova serrata belongs to the botanical family Ulmaceae. This majestic tree, with relatively slow growth, reaches a height of 18 to 20 metres (59 to 66 feet) and a width of approximately 13-15 metres (43-49 feet). It develops a short and stocky trunk from which robust and wide-spreading branches rise, giving rise to finer branches. They form the structure of its wide crown, which has a regular, rounded and relatively sparse shape. The young twigs are green and hairy; they later become smooth and brownish-red. The young bark of this tree is smooth, grey-brown and speckled with pinkish-red to orange. With age, it peels off in small plates that reveal new and vibrant skin of ochre colour. The young spring shoots are purple. The deciduous leaves are more divided than those of the elm: oblong to elliptical, 7 to 13 cm (3 to 5in) long, tapering to a point, adorned with very regular teeth, they are light green, rough on the upper side and glossy on the underside. In autumn, they turn reddish-bronze and yellow-orange. The inconspicuous green flowers appear simultaneously, or just after the emergence of foliage, in April-May. The female flowers, green in colour, are separate from the male flowers, yellow in colour, but carried by the same plant. The latter will bear small kidney-shaped stone fruits, 0.3 cm (1in) in diameter, without wings, changing from green to brown when ripe.

The Japanese Zelkova is reserved for large open spaces. A beautiful shade tree, it can be planted as a solitary specimen or in a row along a main thoroughfare in a park. It can be paired with purple beech, lindens, easy-to-grow maples, or poplars. With its beautiful bark and autumn colours, the Zelkova can be trained as a bonsai.