Dahoon Holly Ilex cassine
INTRODUCTION
Attractive when tightly clipped into a tall screen or allowed to
grow naturally into its single-trunked, small tree form, Dahoon Holly
is ideal for a variety of landscape settings). Capable of reaching
40 feet in height, Dahoon Holly is usually seen at a height of 20
to 30 feet with an 8 to 12-foot spread. The smooth, supple, shiny
dark green, evergreen leaves, two to three inches long, have just
a few serrations near the tip. Possessing male and female flowers
on separate plants, at least two Dahoon Hollies (male and female)
must be planted in the landscape to ensure production of the brilliant
red berries in fall and winter. The berries serve as an excellent
food source for wildlife but are far less prevalent than on East
Palatka or Fosters Holly.
GENERAL INFORMATION
Scientific name: Ilex cassine
Pronunciation: EYE-lecks kuh-SIGH-nee
Common name(s): Dahoon Holly
Family: Aquifoliaceae
USDA hardiness zones: 7 through 11
Origin: native to North America
Uses: Bonsai; container or above-ground planter; hedge; wide tree
lawns (>6 feet wide); medium-sized tree lawns (4-6 feet wide);
recommended for buffer strips around parking lots or for median strip
plantings in the highway; near a deck or patio; reclamation plant;
screen; narrow tree lawns (3-4 feet wide); specimen; sidewalk cutout
(tree pit); residential street tree; tree has been successfully grown
in urban areas where air pollution, poor drainage, compacted soil,
and/or drought are common
Availability: generally available in many areas within its hardiness
range
DESCRIPTION
Height: 20 to 30 feet
Spread: 8 to 12 feet
Crown uniformity: irregular outline or silhouette
Crown shape: oval; pyramidal
Crown density: open
Growth rate: medium
Texture: medium
Foliage
Leaf arrangement: alternate
Leaf type: simple
Leaf margin: entire; serrate
Leaf shape: elliptic (oval); oblong
Leaf venation: pinnate
Leaf type and persistence: evergreen
Leaf blade length: 2 to 4 inches
Leaf color: green
Fall color: no fall color change
Fall characteristic: not showy
Flower
Flower color: white
Flower characteristics: inconspicuous and not showy; spring flowering
Fruit
Fruit shape: round
Fruit length: < .5 inch
Fruit covering: fleshy
Fruit color: red; yellow
Fruit characteristics: attracts birds; attracts squirrels and other
mammals; no significant litter problem; persistent on the tree; showy
Trunk and Branches
Trunk/bark/branches: bark is thin and easily damaged from mechanical
impact; droop as the tree grows, and will require pruning for vehicular
or pedestrian clearance beneath the canopy; routinely grown with,
or trainable to be grown with, multiple trunks; not particularly
showy; tree wants to grow with several trunks but can be trained
to grow with a single trunk; no thorns a strong structure
Breakage: resistant
Current year twig color: green
Current year twig thickness: medium
Culture
Light requirement: tree grows in part shade/part sun; tree grows
in full sun
Soil tolerances: clay; loam; sand; slightly alkaline; acidic; extended
flooding; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: moderate
Other
Roots: surface roots are usually not a problem
Winter interest: no special winter interest
Outstanding tree: not particularly outstanding
Invasive potential: little, if any, potential at this time
Verticillium wilt susceptibility: not known to be susceptible
Pest resistance: long-term health usually not affected by pests
USE AND MANAGEMENT
Growing well in full sun to partial shade, Dahoon Holly does best
on moist soils since the wet, boggy soils of swamps is its native
environment. Dahoon Holly can tolerate drier locations with some
watering, but often has a thin crown in this environment. It is
not recommended in the southern part of its range in a dry, exposed
site unless irrigation is provided. It lends itself well to use
as a specimen or street tree, and is ideal for naturalizing in
moist locations. Little pruning is needed to create a well-structured,
strong tree. It appears to adapt well to the confined spaces of
urban and downtown landscapes and is tolerant of some salt spray.
The crown is fuller in full sun. Ilex cassine var. angustifolia,
Alabama Dahoon, has narrower, more linear leaves than the species
and more abundant but smaller berries. Ilex myrtifolia has smaller
leaves and fruit, and its cultivar ‘Lowei’ has yellow
berries and dark green foliage. Propagation is by seeds, which
germinate in one year, or by cuttings. Cuttings are preferred since
they give plants of a known sex and also root easily.
Pests and Diseases
No pests or diseases are of major concern. A twig gall sometimes
forms in response to a fungus infection. Mites can infest foliage
on trees planted on dry sites.
by Edward F. Gilman and Dennis G. Watson
