Japanese Holly Ilex crenata 'Sky Pencil'

The sky pencil holly is a female cultivar of Ilex crenata, Japanese Holly, a native of Japan and east Asia that can be found in thickets, woods and wet places in lowland and mountains all over Japan. Sky Pencil Holly is a handsome evergreen shrub that is smaller that most of the species at 6 to 8 feet high, is densely branched, tight, and has columnar growth. It has a fastigiate form, meaning narrowing toward the top and having upright, usually clustered, branches that it maintains without pruning. It is a good container or accent plant and works well in formal gardens as it provides a good vertical accent in mixed borders. The Sky Pencil Holly was voted Holly of the Year for 2004 by the Holly Society of America.

Sky Pencil Holly is easy to transplant and urban tolerant. Plant in the full sun to partial shade in acidic well-drained soil though it tolerates a wide range of soil types, from moist to dry, and actually prefers clay. It tolerates shade and air pollution. However, it does not do well in alkaline soils or under drought conditions. It does have a slow growth rate and it may not thrive in areas with high heat and humidity (USDA zones 8 and 9). The species is dioecious (meaning individual flowers are either male or female, but only one sex is to be found on any one plant, thus both male and female plants must be grown if seed is required). It is pollinated by bees and is not self-fertile. Sky Pencil Holly is an all-female cultivar which needs a male pollinizer in order to produce fruit.

Diseases, Insect Pests, and Other Plant Problems:

This plant needs protection from the wind and cold with a wind break and mulching. Spider mites and nematodes are occasional pests.  Alkaline soils will cause the leaves to yellow.

The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common diseases and insect pests.

More information on Ilex crenata.