Ilex crenata 'Caroline Upright' DARK STAR Japanese holly, box-leaved holly
size/type
medium-sized shrub,taller shrub
usual height
1,5-2,5m
usual width
1-2m
leaves
evergreen broadleaf
colour of leaves
location
full sun to shade
soil type
acidic (peaty) to neutral
soil moisture requirements
evenly moist but well-drained
USDA zone (lowest)
5b (down to -27°C)
winter protection
for zone 5+6
for zone 7
categorized
Many people mistake Japanese holly for English box thanks to its small, evergreen leaves. This resemblance was also the main reason why it was chosen to become the hardy substitute for true box which is dying all around Europe as well as in the UK. Japanese holly a versatile, evergreen, and almost maintenance-free plant available in many varieties offering different shapes and sizes.
Description of the plant:
Caroline Upright or DARK STAR is a selection of Japanese holly with upright growth and deep green leaves. Those are small, broadly elliptic, and very glossy. In mid spring opens a profusion of small, creamy white flowers serving plenty of bee food. It is a female variety so if pollinated by a male plant from nearby they are followed by small, black berries in autumn. They are not edible nor poisonous for people but contain saponins which cause severe discomfort if eaten in quantity. They are important bird food in winter. Stems are pale grey-green.It grows about 20-30 cm per year and naturally forms dense, upright growing, many-branched shrubs. You can use it like a box plant - in the same spot or a container or among other large-leaved, evergreen plants to which its delicate foliage will provide a great contrast. As every other Japanese holly it is ideal for bonsai making as well as for hedging. It can be pruned and clipped in almost any way from early spring by end July.
Japanese holly is usually trouble-free, tolerates any soil apart from compacted (clay) and boggy, and can withstand summer dry spells once established. However, for best results and leaf colour grow it in medium fertile, moist but well-drained acid soil. Fully hardy to abt. -27°C (USDA zone 5b) and suitable for outdoor planters, too.
Last update: 09-09-2022
