Japanese Holly Ilex crenata 'Sky Pencil'
Other Common Name(s):
Other plants called Japanese Holly:
- Phonetic Spelling
- EYE-leks kre-NAH-tuh
- This plant has low severity poison characteristics.
- See below
- Description
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‘Sky Pencil’ holly is a female cultivar of Japanese holly (Ilex crenata). ‘Sky Pencil’ is an evergreen shrub with densely branched, tight, columnar (fastigiate) growth habit. It is a member of the holly family (Aquifoliaceae).
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 prefers clay. It tolerates shade and air pollution. However, it does not do well in alkaline soils or under drought conditions. It has a slow growth rate and may not thrive in areas with high heat and humidity (USDA zones 8 and 9). ‘Sky Pencil’ holly is an all-female cultivar that needs a male pollinizer to produce fruit.
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. ‘Sky Pencil’ is a popular cultivar in situations that show off its fastigiate form, such as a formal English garden or as a contrasting accent among low, rounded shrubs in an Asian or winter garden. Because it its distinctive growth habit, it is not suitable for naturalistic landscape designs. ‘Sky Pencil’ was voted Holly of the Year for 2004 by the Holly Society of America.
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 turn yellow.
The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common diseases and insect pests.
- See this plant in the following landscape:
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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- Tags:
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Attributes:
- Genus:
- Ilex
- Species:
- crenata
- Family:
- Aquifoliaceae
- Life Cycle:
- Woody
- Recommended Propagation Strategy:
- Seed
- Stem Cutting
- Country Or Region Of Origin:
- East Nepal to Temperate East Asia, Japan and Korea
- Fire Risk Rating:
- medium flammability
- Wildlife Value:
- The small fragrant flowers attract bees. Members of the genus Ilex support the following specialized bee: Colletes banksi.
- Play Value:
- Wildlife Food Source
- Particularly Resistant To (Insects/Diseases/Other Problems):
- Mildly resistant to damage by deer.
- Edibility:
- Use caution. Human ingestion of berries can cause minor toxic reaction.
- Dimensions:
- Height: 4 ft. 0 in. - 10 ft. 0 in.
- Width: 1 ft. 0 in. - 3 ft. 0 in.
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Whole Plant Traits:
- Plant Type:
- Perennial
- Shrub
- Woody Plant Leaf Characteristics:
- Broadleaf Evergreen
- Habit/Form:
- Columnar
- Dense
- Erect
- Multi-stemmed
- Growth Rate:
- Slow
- Maintenance:
- Medium
- Texture:
- Medium
- Appendage:
- Spines
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Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- Clay
- Loam (Silt)
- Sand
- Soil pH:
- Acid (<6.0)
- Neutral (6.0-8.0)
- Soil Drainage:
- Good Drainage
- Moist
- Occasionally Wet
- Available Space To Plant:
- 3 feet-6 feet
- 6-feet-12 feet
- USDA Plant Hardiness Zone:
- 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
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Fruit:
- Fruit Color:
- Black
- Fruit Value To Gardener:
- Showy
- Display/Harvest Time:
- Fall
- Winter
- Fruit Type:
- Berry
- Drupe
- Fruit Length:
- < 1 inch
- Fruit Width:
- < 1 inch
- Fruit Description:
- Black, globose, berrylike-fruit on pollinated female plants from fall to winter that are 1/4 inch in length. Fruits are hidden below the foliage. Sky Pencil Holly cultivars are all female, thus a male cultivar is required nearby for pollination.
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Flowers:
- Flower Color:
- Green
- White
- Flower Inflorescence:
- Cyme
- Flower Value To Gardener:
- Fragrant
- Flower Bloom Time:
- Spring
- Flower Petals:
- 4-5 petals/rays
- Flower Size:
- < 1 inch
- Flower Description:
- Small (1/4 inch), dull, greenish white fragrant flowers in spring that form in clusters of 1 to 3. Pistillate cyme, in leaf axils of current season's growth; staminate solitary in leaf axils of current season's growth.
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Leaves:
- Woody Plant Leaf Characteristics:
- Broadleaf Evergreen
- Leaf Color:
- Green
- Leaf Feel:
- Glossy
- Leaf Value To Gardener:
- Long-lasting
- Leaf Type:
- Simple
- Leaf Arrangement:
- Alternate
- Leaf Shape:
- Ovate
- Hairs Present:
- No
- Leaf Length:
- < 1 inch
- Leaf Width:
- < 1 inch
- Leaf Description:
- Leaves are alternate, glossy, dark green, slightly convex, and 1 3/8 inches long and 3/4 of an inch wide.
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Bark:
- Bark Color:
- Dark Gray
- Surface/Attachment:
- Smooth
- Bark Description:
- Smooth, gray-brown or slightly greenish.
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Stem:
- Stem Color:
- Green
- Stem Is Aromatic:
- No
- Stem Surface:
- Hairy (pubescent)
- Stem Description:
- Stems are green on current season growth, and turn gray-green to gray-brown by year 2 or 3. They are often densely pubescent on young stems. Dense and rigid at maturity.
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Landscape:
- Landscape Location:
- Container
- Patio
- Walkways
- Landscape Theme:
- Asian Garden
- English Garden
- Winter Garden
- Design Feature:
- Accent
- Border
- Attracts:
- Bees
- Pollinators
- Specialized Bees
- Resistance To Challenges:
- Pollution
