Winterberry Holly

• By Pat Chadwick
• /
• December 2015-Vol.1 No.12
• /
• 4 Comments

As the days grow colder and autumn inevitably gives way to winter, the ornamental garden needn’t be dull or boring. Of the many splendid shrubs and trees that offer color and texture to the winter landscape, Ilex verticillata is guaranteed to ignite your imagination and brighten your spirits. This deciduous member of the holly genus is better known as common winterberry holly. Clearly different from its evergreen relatives, winterberry holly sheds its summer foliage in late autumn exposing masses of densely packed red berries along bare stems. Whether displayed as a single specimen or in a mass planting, this shrub practically shouts: LOOK AT ME!! And so we do – with pleasure.

DESCRIPTION  

Winterberry holly is native to the entire eastern half of North America. It can be found growing from Nova Scotia to Florida in bogs, swamps, damp thickets, low areas, and along ponds and streams. In wet sites in the wild, it may form large thickets or colonies from suckers. In dry soil, it remains a tight shrub. In the ornamental landscape, this holly prefers average to moist soil, but thrives in a wide range of soil types and conditions.

This slow-growing, multi-stemmed shrub typically develops an upright to rounded habit and grows between 5 and 15 feet tall. The leaves are typically two to three inches long, elliptic, toothed, and dark green. In the fall, the foliage turns yellow or, in some cases, maroon. The berries provide significant color and interest in the winter landscape.

Winterberry hollies are dioecious. In other words, the shrubs are either male or female. Both male and female plants produce flowers, but only fertilized flowers on female winterberry shrubs produce berries. The flowers appear either singly or in small clusters along the stems. Each blossom has a green ovule in the center.  Flowers on male winterberries appear in large clusters with several prominent yellow anthers protruding from the center of each blossom.

Sources vary on the ratio of males to females needed for good pollination. In general, one male winterberry holly is adequate for pollinating three to six or more female plants. To ensure pollination, a male winterberry holly must be planted within 40 to 50 feet of a female winterberry holly. Because some males are early blooming and others are late blooming, the appropriate male must be in bloom at the same time as the female. If properly pollinated, the female flowers give way to a crop of bright red berries in late summer to fall. The berries normally persist throughout the winter (hence the common name) and often into early spring.

USES FOR WINTERBERRY HOLLY IN THE LANDSCAPE

• Winterberry holly is an excellent choice for a rain garden because of its ability to tolerate both moist and dry soils.
• Suitable for shrub borders, hedges, foundation plantings, and native plant areas, it looks particularly attractive grouped in mass plantings.
• While attractive in a mixed border, winterberry holly is particularly eye catching when planted in front of taller evergreens.  The red berries contrast well against the dark green background. They also show well in front of fences and stone walls.
• Winterberries attract more than 40 species of birds, including cedar waxwings and robins, according to the Arbor Day Foundation website. Overwintering birds generally don’t eat the bitter and astringent berries until their other food supplies are gone.
• If you have room in your landscape, plant several winterberry hollies so that you can clip the heavily berried branches for use in floral arrangements.

WINTERBERRY HOLLY CULTIVARS

Although winterberry holly is an attractive shrub, the species is infrequently sold commercially because many excellent cultivars produce larger, more abundant fruit. A few examples of commercially grown female cultivars and suggested male pollinators include:

• ‘Berry Heavy®’ – Size: 6 to 8 ft. tall and wide. Just as its name suggests, this female cultivar produces abundant bright red fruit. Its shiny foliage takes on a purplish-bronze tint in autumn. Pollinator: Early-blooming ‘Jim Dandy’
• ‘Berry Nice®’ – Size: 6 to 8 ft. tall and 3 to 5 ft. wide. It produces deep-red berries in stark contrast to its autumn foliage. Pollinator: ‘Jim Dandy’.
• ‘Bonfire’ –   Size: 8 ft. tall and wide. A hybrid between Ilex verticillata (North American) and I. serrata (Japanese Finetooth holly), this cultivar grows more rapidly than the species and produces masses of small red berries at a young age. Pollinator: ‘Apollo,’ ‘Jim Dandy,’ or ‘Southern Gentleman’.  
• ‘Cacapon’ – Size: 6 to 8 ft. tall and wide. This cultivar has a nice upright rounded habit and is distinguished from other winterberries by its crinkled, glossy dark green leaves. It has abundant bright red fruit and makes a great landscape plant with year round interest. Pollinator: ‘Jim Dandy’.
• ‘Red Sprite’ – Size: 3 to 5 ft. tall and wide. The smallest of the cultivars, this compact female bears abundant, large, bright red berries and densely spaced, dark green leaves. It is an excellent choice for a smaller garden or for a mixed border. It is also ideal for a mass planting or low hedge.   Pollinator: ‘Jim Dandy’ or ‘Apollo’.
• ‘Sparkleberry’ – Size: 12 ft. tall and wide. Introduced by the United Stated National Arboretum, this is a hybrid of I. verticillata and I. serrata. A fast grower with an upright form, it produces generous quantities of large, brilliant red fruit that persist through the winter. Berries facing the sun may fade. Pollinator: ‘Apollo’ (a hybrid resulting from the same breeding program and the same cross as ‘Sparkleberry’). 
• ‘Winter Red’ – Size: 6 to 9 ft. with a slightly narrower spread. This female cultivar has an upright habit and is one of the most popular winterberries grown commercially. It produces abundant long lasting, pea-sized, bright red fruits that are very showy in the winter landscape.     Pollinator: Late blooming ‘Southern Gentleman,’ ‘Apollo,’ or ‘Raritan Chief’. 
• ‘Winter Gold’ –Size: 7 ft. tall and wide. If you’re looking for something a little different, consider this yellow-berried female sport of ‘Winter Red’. The berries initially ripen to a pinkish-orange color, which lightens with age. Pollinator: ‘Southern Gentleman’. 
• ‘Apollo’ – Size: 10 to 12 ft. tall and wide. This upright male hybrid of I. verticillata and I. serrata was introduced by the U.S. National Arboretum and is the late-blooming pollinator of choice for ‘Red Sprite,’ ‘Bonfire,’ and ‘Sparkleberry’. The new growth is burgundy red.
• ‘Jim Dandy’ – Size: 5 ft. tall and slightly wider. This dwarf male clone is a pollinator for early flowering winterberries such as Berry Heavy®, Berry Nice®, ‘Red Sprite,’ ‘Afterglow,’ and ‘Aurantiaca’.
• ‘Southern Gentleman’ – Size: 6 to 9 ft. tall and wide. This late-blooming male clone is the pollinator of choice for late-blooming female clones, including ‘Winter Red,’ ‘Winter Gold,’ ‘Cacapon,’ and ‘Sparkleberry’.

CARE AND MAINTENANCE OF WINTERBERRY HOLLIES

• Ideal Planting Time: Early autumn so that their roots can become well established before winter.

• Sunlight Requirements: Full sun to part shade. Full sun will result in better berry production.

• Moisture Requirements: Prefers medium to wet soils but will tolerate average garden soil. If planted in a drier site, they may need to be watered periodically during hot, dry weather.

• Soil pH Range: 3.8 to 6.0 or slightly acidic soil. They will not thrive in alkaline soil.

• Maintenance: None other than an occasional pruning to maintain size or to remove dead or damaged growth. Prune to shape in late winter or early spring before new growth appears.

• Propagation: Winterberries may be propagated from softwood cuttings. From early spring to midsummer, clip 6- to 8-inch long cuttings from the ends of green, pliable winterberry branches. Select cuttings from both male and female plants since both are needed for successful fruit set.

PROBLEMS

Winterberries have no serious insect or disease problems other than occasional leaf spots and mild powdery mildew on the foliage. Neither condition poses any significant problem.

Deer may occasionally browse winterberries but seldom severely damage them. Of the dozen or so winterberries planted in my landscape south of Charlottesville, I have not observed any damage from deer browsing.  However, I have observed damage to two of the shrubs caused by male deer rubbing their antlers on the branches to shed the “velvet.” Fortunately, the shrubs recovered in one growing season.

SUMMARY

No matter which cultivar you select, winterberry holly is a glorious shrub worth including in your winter landscape. Better yet, choose several of them if you have room. This tough but beautiful, easy-to-grow shrub lights up the winter landscape with its festive and colorful berry display. Moreover, the birds will appreciate the berries over the winter months.

SOURCES

Arbor Day Foundation website (http://www.arborday.org).

Piedmont Virginia Native Plant Database (http://www.albemarle.org/NativePlants/list.asp)

Dirr, Michael, A., Dirr’s Hardy Trees and Shrubs (1997)

Rutgers New Jersey Agricultural Experiment Station, Landscape Plants Rated by Deer Tolerance, https://njaes.rutgers.edu/deerresistance/

Mellichamp, Larry, Native Plants of the Southeast (2014)

State Arboretum of Virginia Website, Deer “Resistant” Plant List, (http://www.virginia.edu/blandy)

The United States National Arboretum website (http://www.usna.usda.gov/

United States Department of Agriculture Natural Resources Conservation Service Website:   (http://plant-materials.nrcs.usda.gov/)

Virginia Cooperative Extension Publication 450-236, Problem-Free Shrubs for Virginia Landscapes, http://pubs.ext.vt.edu/450/450-236/450-236.html

Virginia Cooperative Extension Publication 2901-1077, Winterberry (Ilex verticillata), https://pubs.ext.vt.edu/2901/2901-1077/2901-1077_pdf.pdf