A Korean boxwood is a slow growing evergreen plant, meaning that it does not drop its leaves during winter, but instead retains them all year round. If the plant is in good health, its leaves have a vivid, shiny green during the spring and summer, and take on a yellow to purple hue in winter. Reaching about 4 feet (1.2 meters) high and wide, the Korean boxwood is commonly used as a short hedge and is pruned and trimmed to encourage denser growth. The Korean boxwood produces tiny yellow flowers in spring which are very fragrant.
This species is hardy and can tolerate a wide range of conditions. Able to survive temperatures as low as -20° Fahrenheit (-29° Celsius), it can also tolerate high humidity, full sun to partial shade, and nutrient poor soil. It will not, however, thrive in heavy clay soil; it also has a narrow range of suitable pH and should not be exposed to strong winds. The plant also requires good drainage, as it will not endure water logging. If the plant becomes water logged, or the soil has poor drainage, root rot will most likely set in.
The Korean boxwood does not suffer damage from deer and other forage animals because the plant is unpalatable and poisonous if consumed. This species is also poisonous to humans if eaten; it is important to ensure that hands are thoroughly cleaned after working with this plant. Although resistant to grazing and foraging animals, the plant is susceptible to attack from a number of insects. Insect infestation can cause extensive damage, poor general health, and large wounds which leave the plant more vulnerable to fungal and bacterial infections.
Fungal and bacterial diseases can be a serious issue for the Korean boxwood. Similar to insect infestation, diseases and infections need to be caught early so that appropriate treatment can be administered before too much damage is caused. To minimize the risk of insect attacks or infection and disease, any organic matter, such as grass clippings and dead leaves, should be removed from the base of the plant. Some insect larvae and fungal and bacterial diseases can over winter in this type of organic matter.
As first generation hybrid, the Korean boxwood does not produce viable seed. A first generation hybrid is created by crossing two different species with particularly attractive qualities. The seed produced by the hybrid is then a second generation hybrid. If the seeds do germinate, the plants are considered to be unstable hybrids. This means that the plants may not reach maturity and may have poorer general health or a range of other undesirable characteristics.
New plants cannot be grown using seed from the Korean boxwood because of its hybrid nature. New plants must be grown by taking stem cuttings from mature plants. New plants can also be propagated by dividing the roots of mature plants. Cuttings are the easier, more reliable option. Dividing the roots is not always practical, and can be problematic, causing extensive damage and even death to the established Korean boxwood.