Ulmus davidiana var. japonica
Ulmus davidiana var. japonica (Japanese elm)
The Japanese elm is a large, graceful elm native to northeast Asia and Japan. It grows in swamp forests on young, rich soils, but much of that habitat has disappeared due to rice farming. Some authorities treat japonica as its own species (U. japonica) rather than a variety of U. davidiana.
Size and form vary a lot. Some trees have a broad, densely branched crown, while others are tall with a narrow crown. A famous example near Iwamigawa, Hokkaido, was about 34 meters tall with a clean trunk up to 15 meters high. There are local cork-barked forms (f. suberosa) and smooth-leaved forms (f. kijimae). Young shoots can be corky and may be roughened with tiny warts. Leaves are obovate, up to 11 cm long, with a roughly 10 mm petiole, and they stay green late into autumn before turning a deep yellow.
Flowers appear in early spring before the leaves; they are tiny and lack petals. The fruit is a small, under-15 mm samara, obovate to round, sometimes hairy.
Growth and reproduction: trees grown from seed in England flowered after about 13 years. This elm does not sucker from roots.
Disease and pests: natural populations have low to moderate resistance to Dutch elm disease. In the Netherlands, the more vigorous trees tended to suffer more leaf damage after infection. In North America, careful selection has produced several cultivars that are highly resistant to the disease. The tree is resistant to elm leaf beetles but is moderately susceptible to elm yellows.
Horticulture and history: Japanese elm has long been used as a street tree in northern Japan. It was introduced to the United States at the Arnold Arboretum in 1895 and to Kew Gardens in 1897. In Europe, Späth’s nursery started marketing it around 1900. Some early specimens in Britain may still survive. A form once called U. wilsoniana (from western China) was brought to North American collections and has been confused with U. japonica in the past.
Breeding and planting abroad: in 1977, a Dutch breeder collected the tree in Japan for use in elm-breeding programs. This helped create small plantations in the Netherlands and contributed to European breeding stock.
Cultivars and trials: several hardy cultivars were developed in Canada and the United States, and some were grown in the UK. Notable cultivars include a range that are resistant to Dutch elm disease, such as some selections released for trials and conservation. In the UK, plantings have shown good tolerance of heavy clay soils, dry chalk, and winter waterlogging, though growth can be slower and flushing later in spring. Butterfly Conservation trials noted tolerance to dry and wet conditions, with some limited impact on local butterflies.
Other notes: the species does not spread by root suckers, and its leaves and overall habit can vary greatly between trees, from broad, spreading forms to tall, narrow ones.
This page was last edited on 2 February 2026, at 08:34 (CET).