Plant Guide with Characteristics, Classification, and other detailed information

Plant Guide

Ilex opaca Ait.
American holly
ILOP

Summary
Duration	Perennial
Growth Habit	Tree, Shrub
U.S. Nativity	Native to U.S.
Federal T/E Status
National Wetland Indicator	FACU, FAC-

Morphology/Physiology
Active Growth Period	Spring and Summer
After Harvest Regrowth Rate
Bloat	None
C:N Ratio	High
Coppice Potential	No
Fall Conspicuous	Yes
Fire Resistant	No
Flower Color	Yellow
Flower Conspicuous	No
Foliage Color	Green
Foliage Porosity Summer	Dense
Foliage Porosity Winter	Dense
Foliage Texture	Coarse
Fruit/Seed Color	Red
Fruit/Seed Conspicuous	Yes
Growth Form	Single Stem
Growth Rate	Slow
Height at 20 Years, Maximum (feet)	20
Height, Mature (feet)	60
Known Allelopath	No
Leaf Retention	Yes
Lifespan	Moderate
Low Growing Grass	No
Nitrogen Fixation
Resprout Ability	Yes
Shape and Orientation	Erect
Toxicity	None

Growth Requirements
Adapted to Coarse Textured Soils	No
Adapted to Fine Textured Soils	Yes
Adapted to Medium Textured Soils	Yes
Anaerobic Tolerance	Low
CaCO3 Tolerance	Low
Cold Stratification Required	Yes
Drought Tolerance	Medium
Fertility Requirement	Medium
Fire Tolerance	Low
Frost Free Days, Minimum	140
Hedge Tolerance	Medium
Moisture Use	Medium
pH, Minimum	4
pH, Maximum	7.5
Planting Density per Acre, Minimum	300
Planting Density per Acre, Maximum	800
Precipitation, Minimum	36
Precipitation, Maximum	60
Root Depth, Minimum (inches)	30
Salinity Tolerance	Low
Shade Tolerance	Tolerant
Temperature, Minimum (°F)	-18

Reproduction
Bloom Period	Mid Spring
Commercial Availability	Routinely Available
Fruit/Seed Abundance	Low
Fruit/Seed Period Begin	Summer
Fruit/Seed Period End	Fall
Fruit/Seed Persistence	Yes
Propagated by Bare Root	Yes
Propagated by Bulb	No
Propagated by Container	Yes
Propagated by Corm	No
Propagated by Cuttings	Yes
Propagated by Seed	Yes
Propagated by Sod	No
Propagated by Sprigs	No
Propagated by Tubers	No
Seed per Pound	28430
Seed Spread Rate	Slow
Seedling Vigor	Low
Small Grain	No
Vegetative Spread Rate	None

Suitability/Use
Berry/Nut/Seed Product	Yes
Christmas Tree Product	Yes
Fodder Product	No
Fuelwood Product	Medium
Lumber Product	No
Naval Store Product	No
Nursery Stock Product	Yes
Palatable Browse Animal	Low
Palatable Graze Animal	Low
Palatable Human	No
Post Product	No
Protein Potential	Low
Pulpwood Product	No
Veneer Product	No

Kingdom Plantae -- Plants

Subkingdom Tracheobionta -- Vascular plants

Superdivision Spermatophyta -- Seed plants

Division Magnoliophyta -- Flowering plants

Class Magnoliopsida -- Dicotyledons

Subclass Rosidae

Order Celastrales

Family Aquifoliaceae -- Holly family

Genus Ilex L. -- holly P

Species Ilex opaca Ait. -- American holly P

Uses

The attractive evergreen foliage and bright red fruit of this small tree make it a very popular for landscaping. The same attributes that allow this tree to be a desirable ornamental make it one of the most sought after greens for Christmas decoration. The firm bright red berries are consumed by white-tail deer and 18 species of birds. The dense foliage also provides cover and nesting habitat for various songbirds.

Status

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).

Description

American holly normally grows to heights of 15 to 30 feet tall, but records indicate mature heights of up to 100 feet. On the poor soils of coastal beaches, this holly may never exceed shrub size. The bark of it is smooth, and grayish to grayish-brown. The dense branches of this holly grow nearly horizontal in a spreading crown, which takes on a pyramidal silhouette.

The evergreen foliage is stiff and leathery in texture, with large, remotely spined teeth. The leaves are arranged alternately. They are 2 to 4 inches long, satin green and smooth above, and yellowish-green below.

Small, axillary, greenish-white flowers bloom from April to June. Like most others in the holly genus, American holly is dioecious. Pistillate flowers emerge in small clusters from one plant, while staminate flower clusters develop on another. Newly established plants will not flower for 4 to 7 years; prior to flowering there is no practical means of determining the gender of a plant. Bright red, rarely orange or yellow, globular fruit mature from September to October, but may be retained on the plant into the following spring. The berry-like fruit is about 1/3 inch in diameter, and contains 4 to 9 small nutlets. There are an average of 28,430 seeds per pound.

Adaptation and Distribution

American holly grows from Massachusetts to Florida, west to Texas and Missouri, and is adapted to a wide range of site conditions. It grows best on well drained, sandy soils, but will tolerate those which are somewhat poorly drained. This small tree has good shade tolerance, but does well in direct sun. Although this species is often found growing on coastal sand dunes, it is not very salt spray tolerant.

For a current distribution map, please consult the Plant Profile page for this species on the PLANTS Website.

Establishment

Utilize standard tree and shrub planting Precautions to establish containerized or balled and burlapped plants. Bare rooted transplants usually have marginal success.

When establishing American holly, it is important to plant males as well as females if berry production is desired. In a nursery situation the gender ratio should be 1:10, males to females. Establish American holly only where surrounding vegetation or physical barriers protect the plants from harsh winds. Holly plants prefer partial shade, with some full sun exposure during the day.

Cultivars, Improved, and Selected Materials (and area of origin)

There are many ornamental varieties, available from commercial nurseries, selected for berry and leaf color. There are also commercial sources of locally and regionally collected material available from native plant nurseries.

Prepared By & Species Coordinator:

USDA NRCS Plant Materials Program

Edited: 05Feb2002 JLK; 060801 jsp

For more information about this and other plants, please contact your local NRCS field office or Conservation District, and visit the PLANTS Web site<https://plants.usda.gov> or the Plant Materials Program Web site <https://Plant-Materials.nrcs.usda.gov>

Attribution: U.S. Department of Agriculture