Gardeners in northern climates are faced with a challenge in keeping the landscape interesting when the last of the autumn flowers and colorful fall foliage have faded. Winter is a time when many gardeners resign themselves to a dreary winter landscape, spending their time planning next year's garden. But if your landscape has been well planned, winter need not be a time of colorlessness.
Winterberry (Ilex verticillata), a deciduous holly shrub that is native to the eastern U.S., can be a great addition to the landscape, as it produces bright red berries that persist through the entire winter and into spring. Not only do the bright berries add important color to winter landscapes, but they also lure in colorful birds that love to feed on the prolific red berries.
Unlike other familiar holly shrubs, winterberry is a deciduous shrub rather than an evergreen. Although one might view this as a drawback, it proves to be a beneficial trait, since it allows the exciting display of red berries to come to the forefront as winter arrives. All the attention is drawn to the plant's fruit, with no foliage to obstruct the view.
Winterberry is a slow-growing shrub with a rounded upright growth habit. It typically grows 3 to 15 feet tall and readily suckers to form large thickets. The leaves are dark green and elliptical, about 2 to 3 inches long. Fall color is usually not impressive, although some years may see the foliage turn an attractive maroon color. Fairly plain greenish-white flowers appear in spring, which, if properly pollinated, produce a dense crop of 1/4-inch-diameter, bright red berries in late summer and fall.
|Botanical Name||Ilex verticillata|
|Common Names||Winter hollyberry, hollyberry, black alder, false alder, fever bush|
|Plant Type||Deciduous shrub|
|Mature Size||3 to 15 feet tall and wide, depending on variety|
|Sun Exposure||Full sun to part shade|
|Soil Type||Medium-moisture to wet soil|
|Soil pH||4.5 to 6.5 (acidic)|
|Bloom Time||June to July|
|Hardiness Zones||3 to 9 (USDA)|
|Native Area||Moist swamps and thickets in southeast Canada and Eastern U.S.|
|Toxicity||Toxic to humans and animals|
Winterberry Holly Care
In nature, winterberry shrubs typically call wetland areas home, which makes them ideal for routinely wet or poorly drained areas of a home landscape (where little else will grow). But it also grows in a variety of conditions, as long as it gets enough moisture. Winterberry is generally pest- and disease-resistant but can be susceptible to leaf spots and powdery mildew, which are rarely serious.
Winterberry is a dioecious plant, which means there are separate male and female plants. Because only fertilized female plants will produce a wonderful display of berries, it is crucial that there be at least one male winterberry plant in the area to allow for cross-pollination. Generally, a single male shrub can pollinate 6 to 10 female shrubs.
Winterberry holly will do well in either full sun or part shade.
This plant adapts to both light and heavy soils but performs best in acidic loam with a good level of organic material. It does poorly in neutral to alkaline soil, which can cause fatal chlorosis (yellowing of the leaves). Feeding with an acid fertilizer can prevent this.
Winterberry holly prefers fairly wet conditions. Do not plant it in dry soil or in a dry climate unless you are willing to water frequently. This plant will require 1 inch of water per week, either through rainfall or irrigation.
Temperature and Humidity
Wiinterberry has a good tolerance for all temperature and humidity conditions across its hardiness range, though it does not do well in conditions of prolonged dryness.
Winterberry usually doesn't require feeding unless growth is very slow. Where needed, 1/2 cup of balanced 10-10-10 fertilizer applied each spring usually is sufficient. Where alkaline soil is a problem, an acid fertilizer may help.
Is Winterberry Holly Toxic?
Like all hollies, winterberry is mildly toxic to some animals and to people. The berries contain a caffeine-like alkaloid called theobromine which, in large doses, can cause dizziness, elevated pulse, nausea, and diarrhea. Don't use this plant where children, dogs, or cats are likely to eat the berries.
Varieties of Winterberry Holly
Planting one of the many good cultivars may be preferable to planting the native species, since the growth characteristics of the cultivars are often preferable to those of the native form. Buying from a nursery can also ensure that you get at least one male plant, necessary for pollination and production of berries.
- 'Oosterwijk' is a Dutch cultivar noted for branches that work well in floral displays. This shrub's branches hold their color and berries very well in flower arrangements. This cultivar grows 4 to 6 feet in height.
- 'Winter Red' is a multi-stemmed shrub that produces its red berries in an especially vigorous abundance. Mature plants grow to 8 to 9 feet in height.
- 'Cacapon' has attractive, dark, glossy green leaves and compact branching. Mature plants are 6 to 8 feet in height, with an appealing rounded growth habit.
- 'Red Sprite' is a great low mounded shrub that grows to 3 to 5 feet in height. It works well as a low hedge plant or in mass plantings, as its branches remain dense right down to ground level.
- 'Winter Gold' is a yellow-berried sport of 'Winter Red'. The berries are pinkish-orange, growing lighter as they age. The shrub grows 5 to 8 feet in height.
- 'Aurantiaca' is another color variation, again with bright pinkish-orange fruit. It grows 6 to 8 feet in height.
- 'Berry Poppins' is a great dwarf version that grows to only 3 to 4 feet in height.
- 'La Have' is another good dwarf shrub, topping out at 3 feet in height.
Because the flowers (and resulting berries) appear on new growth, this shrub should be pruned to shape in early spring, just before new growth appears. Pruning is recommended because these shrubs not only grow tall, they also sucker profusely if not controlled. Remove up to (but no more than) 1/3 of the branches each year. Target the oldest branches, and prune them down to ground level.
Propagating Winterberry Holly
Although it's tempting to try planting seeds produced by the plentiful berries, winterberry is more effectively propagated by snipping and rooting stem cuttings, which will grow much faster than seeds.
In late spring through mid-summer, cut several 2- to 3-inch-long stem tips, then remove all but the top pair of leaves. Dip the lower part of the stem in rooting hormone, then insert the cut end into a pot filled with standard potting soil. Cover the entire pot with plastic to keep humidity in until the roots form. Periodically water the cuttings and keep them in a shady outdoor location. After a month, remove the plastic and continue to grow the cutting in the pot. By fall, the new plant should be ready to transplant into the garden.
Landscape Uses of Winterberry Holly
Winterberry is one of the rare deciduous shrubs that provide good year-round interest in the garden. It is normally planted in masses or groups for shrub borders, as foundation shrubs, in native woodland gardens, or in bird gardens. Winterberry is notable for being attractive to a variety of birds and other wildlife. When planting it, make sure you are comfortable with inviting animals such as these into your landscape:
- Cedar waxwings
The berry-laden branches of Ilex verticillata are prized by arts and crafts enthusiasts for use in such items as floral arrangements, winter window boxes, wreaths, and kissing balls.