Quercus aliena - Galcham Oak

Quercus aliena, also known as the Blume oak, is a majestic deciduous tree with a broad and rounded crown, very rare in cultivation. It is recognised by its large, veined leaves, green and glossy on the upper side, pale grey on the underside, its beautiful cracked grey bark, and its fuzzy acorns, carried on short stalks. Quercus aliena is an exceptional specimen for enthusiasts of rare trees who have a large plot of land.

The Blume oak belongs to the Fagaceae family, like all oaks. It is native to the eastern half of China, Korea, and Japan. This species grows in monsoon regions, alternating between a dry season and a rainy season. It was introduced to Europe in 1908 (at Kew in England). Quercus aliena forms a massive trunk topped by a wide and rounded crown. The trunk is grey, with deeply cracked and fissured bark. The growth of this tree is moderately fast, reaching 12 to 18 m in height and 6 to 10 m in spread. Its foliage is deciduous. The leaves are oval, with a pointed or rounded tip and a consistently tapered base. They are coarsely toothed and undulate, with 10 to 15 teeth, often blunt on each edge. The veins are well visible and parallel, radiating from the midrib to the tip of each tooth. These leaves measure between 10 and 20 cm in length and between 5 and 11 cm in width. The lamina is glabrous and dark green and shiny on the upper side, while the underside is very pale and covered with a fine down. Each leaf is carried by a petiole measuring between 1.2 and 3.2 cm in length. In autumn, they turn yellow, sometimes even orange-yellow, before falling.

Quercus aliena is monoecious, meaning that the same tree produces male and female flowers in separate locations. It blooms in April-May. The male flower catkins are pendulous, while the female flowers are arranged in spikes. The fruits, called acorns, are usually solitary, but can sometimes be grouped in pairs or threes. They measure between 1.2 and 2.5 cm in length, with a fuzzy top and a cup enclosing one-third to half of the acorn. The scales are appressed and fuzzy. The root system of this oak is deep and powerful, of a taproot type, ensuring a strong and durable anchorage in the deep soils it prefers.

The Blume oak is a tree for connoisseurs, best reserved for parks and large gardens. It is fairly tolerant, as long as it is planted in a sufficiently deep and not too dry soil. While resistant to cold, it fears late spring frosts. It is preferably planted in an oceanic climate. Tree enthusiasts will plant it alongside a sugar maple (Acer saccharum), a purple beech (Fagus sylvatica 'Atropurpurea'), or a weeping ash tree (Fraxinus excelsior 'Pendula').