Winterberry holly >>>download photo
 

January Gardening Tips
 
 

Feeling the post-holiday blues? Bundle up and go outside to enjoy the swishing sounds of many ornamental grasses and brightly colored berries on hollies and crabapples. If you need something more productive to do, the University of Tennessee Institute of Agriculture recommends these gardening tasks to brighten your winter or make your spring chores less hectic. >>>read the article

UT Gardens' Plant of the Month: Winterberry Holly

by Jeffrey K. Webb

January seems to be the darkest, coldest month of the year, but not all is dreary in the winter garden. Many of the hollies are full of red fruit. Old garden friends like the evergreen Burford Holly (Ilex cornuta 'Burfordii'), Foster Holly (Ilex x attenuata 'Fosteri') and American Holly (Ilex opaca) are reliably full of berries. However, not all hollies are evergreen. Some of the best hollies present their berries on bare stems. Among the top choices of deciduous hollies is the aptly named Winterberry (Ilex verticillata).

Winterberry occurs naturally in swamps, roadside ditches, and other poorly drained areas, often growing with the entire root system submerged for most of the year. This makes Winterberry a good choice for planting in poorly drained areas of the landscape. It also grows well in ordinary garden soil, but best growth and fruiting occurs when the plants do not experience drought. While a Winterberry may grow to a height of 16 feet in the wild, in the landscape the plant will seldom exceed 10 feet. The plant makes an oval to rounded-oval shape, with fine, twiggy branches. It can sucker to make colonies, but seldom does.

When the autumn leaves are falling, the Winterberry fruit is coloring. The bright red berries persist for months on its thin, dark branches, creating a striking picture when laden with snow or displayed against a dark, evergreen background. Gardeners can expect the branches to be heavy with fruit well into mid-winter. The berries are bitter and astringent, so other food supplies will dwindle before overwintering chickadees, blue jays and other birds zero in on the Winterberry fruit. Berries that persist until spring are a favorite of cedar waxwings.

Winterberry grows throughout the eastern half of the U.S., except in West Virginia and most of Kentucky. The closely related Possum Haw (Ilex decidua) is larger and more tree-like, with fruit that is red-orange in color. It is more tolerant of drought and alkaline soils, and is more cold hardy than Winterberry. Numerous selected varieties of both Winterberry and Possum Haw are valuable for use in the landscape.

The Winterberry variety known as Winter Red® is noted for having fruit that persists in good condition for a long time. Winter Red® is compact, growing to a mature size of nine feet tall and eight feet wide. The large, pea-sized fruits are an intense red and are borne in great profusion. Cut stems are reported to keep in good condition indoors for months if not kept in water. Released by the U.S. National Arboretum, the hybrid variety 'Sparkleberry' grows 12 to 15 feet tall with an upright form. Another widely used hybrid, 'Red Sprite' grows to three to five feet and is compact and rounded in shape, with lustrous green leaves and large, abundant berries.

Hollies have either all male flowers or all female flowers, so to have fruit, the gardener must have one male to supply the pollen for every five to seven females, which bear the fruit. Pollinate the Winterberry with the males 'Apollo,' 'Southern Gentleman,' or 'Jim Dandy'. Males should be available at a local garden center or nursery.

Use Winterberry to grace the edge of a pond, where the constant moisture will encourage the plants to form colonies. If you don't have a pond, plant Winterberry where it can show off its fruit against a hedge, an evergreen tree, or a building. Berry-bearing branches are more effective in the landscape when displayed against a dark background.

Winterberry holly has clean foliage through the summer, but its outstanding winter interest can make this low-care shrub the star of your winter garden.

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Jeffrey K. Webb is a graduate student in the University of Tennessee Department of Plant Sciences. He works under the guidance of Dr. Susan Hamilton, director of the UT Gardens. The UT Gardens are located on Neyland Drive in Knoxville. They are free and open to the public seven days a week during daylight hours.

 

 

 
     
 

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