From late fall through winter, Ilex verticillata produces a grand display of bright red berries that persist and light up its branches long after all the leaves have fallen.
Commonly called winterberry, but also known as Michigan holly or swamp holly, this is a deciduous type of holly for cold climates. However, only the female plants produce the colorful berries. Gardeners must plant one male near 3 to 5 females to ensure good pollination and fruiting.
They perform best in full sun in acid moist soils, so they need to be watered in July and August if there is not good rain and be given acid fertilizer.
‘Afterglow’ is a cultivar with big orange-red berries.
In a large planting, it is best to include both early and late blooming male shrubs to maximize pollination of the females. For instance, ‘Jim Dandy’ is a slow-growing dwarf male useful for pollinating early flowering females such as ‘Red Sprite’, which is a popular dwarf female maturing to less than 4 feet tall bearing large red fruits.
A taller variety, ‘Sparkleberry’, matures to 12 feet and has the additional bonus of bearing dark red berries that often persist until spring.
Winterberries are hardy in zones 3 through 9.
