Ilex crenata 'Takakuma-yama' Japanese holly
Ilex
The genus Ilex, commonly known as holly, is very extensive and includes more than 400 species of evergreen and deciduous shrubs and trees, distributed from the tropics of South America through the subtropics of Asia to the temperate zones of Europe. In addition to the possibility of variegated foliage, their greatest advantage is evergreen character, at least in most species, which makes them an excellent complement to deciduous trees and shrubs during the dormant season. Moreover, many hollies naturally lack spines, which will please those who dislike prickly shrubs. The most horticulturally significant are the East Asian species, among which the Japanese holly (Ilex crenata) stands out. This species was described in 1784 by the Swedish botanist Carl Peter Thunberg (1743–1828) during his stay in Japan.
Japanese hollies are very useful and elegant evergreen shrubs that many people at first glance mistake for boxwoods or honeysuckles because of their small, glossy leaves. This very resemblance has predestined them to become the ideal replacement for true boxwoods, which in Europe are gradually disappearing under the pressure of the massive invasion of the box tree moth and due to the fungal disease known as box blight, which has been devastating plantings especially in the British Isles. Japanese hollies, however, are thornless, offer a wide range of shapes and sizes, and require only minimal care. Since they are naturally quite variable, new mutations and cultivars often appear, each slightly different from the last – and every novelty is, of course, a welcome delight.
Takakuma-yama is a Japanese holly variety named by Mount Takakuma near Kagoshima town on Kyushu Island, Japan, because its spreading - outwardly pyramidal habit - resembles a shape of this charismatic mountain. It yields elliptic, dark green leaves. They are evergreen and have a shallow serration at margins.
As a female plant, if pollinated by a male holly nearby, it produces a profusion of small, black, glossy berries in late summer. They are not edible, nor poisonous but contain saponins which can cause severe discomfort if eaten. Blooming time is from late May until June in C.E., Japanese hollies are highly valued melliferous plants offering plenty of bee food. They grow rather slowly.
Japanese holly is tolerant of most soil types except heavy clay, but it thrives best in well‑drained, evenly moist, acidic soil, occasionally enriched with slow‑release fertilizer. It has a strong root system that copes better with poorer conditions than English hollies and adapts easily to the limited root space of containers without showing signs of stress or drought. It is hardy to about −27 °C (USDA zone 5) and is also suitable for outdoor planters with good drainage and where it requires more frequent but careful watering, including during frost‑free winter days.
Last update: 08-02-2021
