Common name: Columnar Japanese holly
Latin name: Ilex crenata ’Sky Pencil’; synonym I.c. ‘Sky Sentry’
Plant type: Shrubs & small trees
Plant size: 4-6′ high x 4-12″ wide
USDA Hardiness Zones: 5-9
Cultural needs: Sun; moist, drained soil
Introduced by the National Arboretum in 1985, columnar Japanese holly is usually called Sky Pencil or Sky Sentry. Whereas so many columnar dwarf trees hail from the conifer side of the plant kingdom, it’s nice to mix in some shiny, evergreen broad leaves. In the photo above, the forest tree in the center is a Sky Pencil. Several others stand tall among columnar junipers and a dwarf Alberta spruce (the only conical shaped tree among the columnar forms). In 10 years, Sky Pencil will still be narrow but it will start looking for clouds to write on. If you lop off the top it flares at the apex, like an ice cream cone. Fortunately it’s forgiving and slow-growing. Trimming whole branches near the top will keep it looking like a tree.
Hollies like a bit more water than most conifers, so plant accordingly by amending the soil to hold moisture. Protect from freezing rain and snow weighing down vertical branches, with burlap or twine. Such a skinny tree fits almost anywhere, hides fences, and groups to make an effective hedge, but its dominant personality also calls attention to whatever it is near, like a vertical sign. Two lustrous Sky Sentries flanking a sunny entrance exude elegance! Learn more at www.monrovia.com/plant-catalog/plants/1528/sky-pencil-japanese-holly.php