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Fosteri Hybrid Holly Ilex x attenuata 'Fosteri'

Other Common Name(s):

Phonetic Spelling
EYE-leks at-ten-yoo-AY-tuh FOS-ter-ee
This plant has low severity poison characteristics.
See below
Description

Foster Holly is a cultivar of Ilex x attenuata and is an evergreen shrub or small tree that has a fine texture, and a dense, slender, conical, or pyramidal shape. It is slow-growing and may reach up to 20 to 30 feet tall and 10 to 15 feet wide. Its leaves are typically spiny, elliptical, and dark olive green. In the spring, small, fragrant, white flowers emerge. An abundance of small, pea-sized orangish-red-to-red berries ripen in the fall and persist through the winter.

Ilex x attenuata is a naturally occurring hybrid cross of Ilex cassine (Dahoon) and Ilex opaca (American Holly). It was initially found growing wild in Florida in the 1920s but is now found throughout the southeastern United States where both parents are native.

'Fosteri' or Fosters Holly, is a cultivar of the Ilex x attenuata. This cultivar represents a group of seedlings that were selected by E.E. Foster of Foster Nursery in Bessemer, Alabama in the 1950s. They are known as the Foster Hybrid Group, and 'Fosteri' is just one of the cultivars in this group.

The genus name, Ilex, is derived from the Latin name, Quercus ilex, for the holm oak whose leaves resemble the leaves of the shrubs in the genus Ilex. The hybrid name, attenuata, means narrowing to a point. This most likely refers to the growth habit of this hybrid.

Foster's Holly grows best in acidic, medium moisture, well-drained soils in full sun to part shade. Although the best fruit production occurs in full sun, these plants do well with some afternoon shade in hot summer climates. You should site the plant where it can be protected from cold winter winds and the soil is well drained. Mulch helps retain soil moisture and deter weed growth. Prune in the winter to maintain a desired size, although keep in mind that the plant flowers are on new growth. Plants can suffer from the cold in USDA Zone 5 and below.  This plant is moderately salt tolerant, air pollution tolerant, and mildly resistant to damage by deer. 

The plants of this species are dioecious, meaning that they have separate male and female plants. The female plant requires a nearby male pollinator plant to produce fruits. Foster's Holly is the rare holly in which female plants produce fruit without fertilization from a male pollinator. Botanically speaking, it is parthenocarpic (from Greek, parthenos meaning virgin, and karpos meaning fruit). Therefore, it is unnecessary to purchase a male foster holly for fruit.

The Foster Holly is ideal for the home landscape as a hedge or screen. It may also be used as a specimen, in small groups, or as foundation plantings. The evergreen foliage and heavy fruit set will add winter interest to your home garden.

Seasons of Interest:

Bloom:  Spring               Foliage:  Year-round          Fruits:  Fall and Winter

Quick ID Hints:

  • finely textured, narrow, conical, or pyramidal-shaped broadleaf evergreen holly
  • smooth, silver-gray bark
  • alternate, elliptical, dark olive green leaves, 1.5 to 3 inches long with tiny, spiny marginal teeth (1 to 4 on each side of the leaf)
  • small fragrant white flowers in the spring
  • orangish-red to red drupes about 0.75 inches in diameter in the fall and winter

Insects, Diseases, and Other Plant Problems: Foster Holly has no serious insect pests or disease problems. Potential insects include holly leaf miners, spittlebugs, spider mites, whitefly, and scale. It is susceptible to leaf spot, leaf rot, tar spot and powdery mildew, leaf drop, leaf scorch, and chlorosis (yellowing of leaves in high pH soils).

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy, and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.

 

More information on Ilex x attenuata.

Profile Video:
See this plant in the following landscape:
Cultivars / Varieties:
  • 'Foster No. 2'
    small to medium size tree, dark green, narrow leaves
  • 'Hume No. 2'
    small leaves
  • 'Sunny Foster'
    variegated pale yellow leaves in full sun
'Foster No. 2', 'Hume No. 2', 'Sunny Foster'
Tags:
#evergreen#small tree#full sun tolerant#specimen#white flowers#wildlife plant#nectar plant#salt tolerant#broadleaf evergreen#winter interest#fall interest#specialized bees#food source wildlife#cpp#deer resistant#children's garden#red fruits#playground plant#acidic soils tolerant#screening#pollinator plant#fantz#evergreen shrub#evergreen tree#bird friendly#winter garden#bee friendly#container plant#alkaline soils intolerant#food source winter#cultivar#pollinator garden#landscape plant sleuths course#hedge
 
Cultivars / Varieties:
  • 'Foster No. 2'
    small to medium size tree, dark green, narrow leaves
  • 'Hume No. 2'
    small leaves
  • 'Sunny Foster'
    variegated pale yellow leaves in full sun
'Foster No. 2', 'Hume No. 2', 'Sunny Foster'
Tags:
#evergreen#small tree#full sun tolerant#specimen#white flowers#wildlife plant#nectar plant#salt tolerant#broadleaf evergreen#winter interest#fall interest#specialized bees#food source wildlife#cpp#deer resistant#children's garden#red fruits#playground plant#acidic soils tolerant#screening#pollinator plant#fantz#evergreen shrub#evergreen tree#bird friendly#winter garden#bee friendly#container plant#alkaline soils intolerant#food source winter#cultivar#pollinator garden#landscape plant sleuths course#hedge
  • Attributes:
    Genus:
    Ilex
    Species:
    cassine x opaca
    Family:
    Aquifoliaceae
    Life Cycle:
    Woody
    Recommended Propagation Strategy:
    Seed
    Stem Cutting
    Fire Risk Rating:
    low flammability
    Wildlife Value:
    Fruits are attractive to birds. Flowers attract bees. Some birds and animals feed on the fruit and foliage in the winter. Members of the genus Ilex support the following specialized bee: Colletes banksi.
    Play Value:
    Buffer
    Edible fruit
    Screening
    Wildlife Food Source
    Edibility:
    Use caution. Human consumption of berries can cause minor toxic reaction.
    Dimensions:
    Height: 20 ft. 0 in. - 30 ft. 0 in.
    Width: 10 ft. 0 in. - 15 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Shrub
    Tree
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Habit/Form:
    Columnar
    Conical
    Dense
    Erect
    Open
    Pyramidal
    Growth Rate:
    Slow
    Maintenance:
    Medium
    Texture:
    Fine
    Appendage:
    Spines
    Thorns
  • 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
    High Organic Matter
    Loam (Silt)
    Sand
    Shallow Rocky
    Soil pH:
    Acid (<6.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Dry
    Very Dry
    Available Space To Plant:
    6-feet-12 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
  • Fruit:
    Fruit Color:
    Orange
    Red/Burgundy
    Fruit Value To Gardener:
    Showy
    Display/Harvest Time:
    Fall
    Winter
    Fruit Type:
    Berry
    Drupe
    Fruit Length:
    < 1 inch
    Fruit Width:
    < 1 inch
    Fruit Description:
    This plant produces abundant round, bright orange-red to red berry-like drupes. The drupes are about 0.75 inches in diameter. They ripen in the fall and persist into winter.
  • Flowers:
    Flower Color:
    Green
    White
    Flower Inflorescence:
    Cyme
    Insignificant
    Flower Bloom Time:
    Spring
    Flower Size:
    < 1 inch
    Flower Description:
    The flowers are small, inconspicuous, fragrant, and white that bloom in the late spring. They measure less than 1 inch in diameter.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Leaf Color:
    Green
    Leaf Feel:
    Glossy
    Leathery
    Smooth
    Waxy
    Leaf Value To Gardener:
    Long-lasting
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Elliptical
    Oblong
    Ovate
    Leaf Margin:
    Serrate
    Hairs Present:
    No
    Leaf Length:
    1-3 inches
    Leaf Width:
    < 1 inch
    Leaf Description:
    The leaves are alternate, simple, elliptic to oblong-ovate, and spinose with 1 to 4 spiny teeth on each side on the upper half of the leaf. The leaves are glossy, dark olive green, and measure 1.5 to 3 inches long. Leaf bases are cuneate.
  • Bark:
    Bark Color:
    Dark Gray
    Light Gray
    Surface/Attachment:
    Smooth
    Bark Description:
    The bark is smooth and silver-gray on the mature plants.
  • Stem:
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Coastal
    Container
    Lawn
    Naturalized Area
    Recreational Play Area
    Slope/Bank
    Landscape Theme:
    Pollinator Garden
    Winter Garden
    Design Feature:
    Accent
    Border
    Hedge
    Mass Planting
    Small groups
    Specimen
    Attracts:
    Bees
    Pollinators
    Small Mammals
    Songbirds
    Specialized Bees
    Resistance To Challenges:
    Deer
    Pollution
    Salt
    Problems:
    Poisonous to Humans
  • Poisonous to Humans:
    Poison Severity:
    Low
    Poison Symptoms:
    Minor toxicity. Ingestion may cause vomiting, diarrhea, or other illness in humans.
    Poison Toxic Principle:
    Saponins
    Causes Contact Dermatitis:
    No
    Poison Part:
    Fruits