Winterberry Holly, Black Alder 'Bright Horizon'

Ilex verticillata

Family: Aquifoliaceae (a-kwee-foh-lee-AY-see-ee) (Info)
Genus: Ilex (EYE-leks) (Info)
Species: verticillata (ver-ti-si-LAH-tuh) (Info)
Cultivar: Bright Horizon
Hybridized by Polly Hill
Registered or introduced: 1972



Foliage Color:

Unknown - Tell us

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Requires consistently moist soil; do not let dry out between waterings

Very high moisture needs; suitable for bogs and water gardens

Where to Grow:

Unknown - Tell us


6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)


6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)

12-15 ft. (3.6-4.7 m)


USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Sun Exposure:

Full Sun

Sun to Partial Shade

Light Shade



Bloom Color:

White/Near White

Bloom Time:

Late Spring/Early Summer




Provides winter interest

Other details:

Unknown - Tell us

Soil pH requirements:

4.6 to 5.0 (highly acidic)

5.1 to 5.5 (strongly acidic)

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Patent Information:


Propagation Methods:

From softwood cuttings

From semi-hardwood cuttings

By simple layering

Seed Collecting:

Remove fleshy coating on seeds before storing

Properly cleaned, seed can be successfully stored

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed


This plant has been said to grow in the following regions:

Poplar Grove, Illinois

Clermont, Kentucky

Lexington, Kentucky

Gardeners' Notes:


On Jan 25, 2012, ViburnumValley from Scott County, KY (Zone 5b) wrote:

'Bright Horizon' Winterberry Holly is one of the first (along with 'Earlibright') of many excellent plants evaluated and selected by the late Polly Hill of Martha's Vineyard. Of her many choice winterberries, this is one of the few that I have yet to acquire.

'Bright Horizon' forms dark reddish orange fruit that are reasonably persistent on a relatively compact and hardy frame. This selection needs no additional assistance other than reasonable moisture during the driest times in the growing season (and an appropriate male plant for pollination). Like all winterberries, it prefers wetness and acid soils on the sandy side.

Polly Hill left quite a legacy of horticultural endeavor at her property (formerly Barnard's Inn Farm, now Polly Hill Arboretum), and the ... read more