Ilex crenata (Japanese Holly or Box-leaved Holly (Japanese: イヌツゲ inutsuge) is an evergreen shrub native to eastern China, Japan, Korea, Taiwan, and Sakhalin. Japanese Holly is grown as an ornamental plant for its dense evergreen foliage. It is superficially similar in appearance to box (Buxus), and is often used in similar situations; it can readily be distinguished from box by its alternate, not opposite, leaf arrangement.
It is an evergreen shrub or small tree growing to a height of 3–5 m (rarely 10 m) tall, with a trunk diameter up to 20 cm. The leaves are glossy dark green, small, 10–30 mm long and 10–17 mm broad, with a crenate margin, sometimes spiny. The flowers are dioecious, white, four-lobed. The fruit is a black drupe 5 mm diameter, containing four seeds. It grows well in acidic soil, between a pH of 3.7 and 6.0.
Grows best in part shade, but tolerates both deep shade (where it will have a looser habit) and full sun (though it can be susceptible to spider mites if in an exposed location). Like most hollies it prefers a deep, humus-rich, well-drained soil.
Numerous cultivars have been selected, including plants with the leaves variegated (e.g. 'Golden Gem', 'Shiro-Fukurin'), dark green (e.g. 'Green Lustre'), or greyish-green (e.g. 'Bad Zwischenahn'); with yellow fruit (e.g. 'Ivory Hall'); and with the habit erect (e.g. 'Chesapeake'), spreading (e.g. 'Green Island', 'Hetzii'), or dwarf (e.g. 'Mariesii', 'Stokes').
Often grown as hedges or topiaries.
Tolerates severe pruning and even coppicing.
Cultivars generally propagated through cuttings.
Pests and Diseases
See Ilex for a list of pests and diseases affecting the genus.
- Germplasm Resources Information Network: Ilex crenata
- Osaka hundred trees: Ilex crenata (in Japanese; google translation)
- Okayama Science University: Ilex crenata (in Japanese; google translation)
- Huxley, A., ed. (1992). New RHS Dictionary of Gardening. Macmillan ISBN 0-333-47494-5.
|Wikiversity is collecting bloom time data for Ilex crenata on the Bloom Clock|