DEPARTMENTS


Ilex decidua





Photos courtesy of Dr. David L. Morgan

It has been said that if it weren't for Ilex decidua (possum haw) in some parts of the natural landscape, there wouldn't be any winter color at all. That's probably true, especially deep in the woods along creeks and rivers in the Midwestern and Southeastern U.S.

Name: Ilex decidua

Common name: Possum haw (also known as bearberry, winterberry, deciduous holly, meadow holly, prairie holly, swamp holly and welk holly)

Hardiness: Zone 5

Mature height: 20 feet in cultivation; 8 feet to 15 feet in nature

Mature spread: 15 feet in cultivation; 8 feet to 10 feet in nature

Classification: Deciduous shrub to small tree

Landscape use: Specimen plant; shrub or tree hedge

Ornamental characteristics: Lovely winter appearance with crimson, scarlet, orange or almost yellow berries; white flowers appear from March to May; attractive in summer with gray bark and small, glossy, dark green leaves; rich yellow foliage in fall

A true holly and member of the Aquifoliaceae, I. decidua is also known variously as bearberry, winterberry, deciduous holly, meadow holly, prairie holly, swamp holly and welk holly. Possum haw, the most common of common names, is derived from the opossums that browse it and its close appearance to hawthorn when in fruit.

Female possum haw is easily spotted from November to February when it is laden with crimson, scarlet, orange or almost yellow berries. The photos you see here are of a typically red-fruited specimen in Fort Worth, Tex., in November.

White flowers appear abundantly from March through May. Even when not in bloom, possum haw has an attractive appearance, with thick, horizontal and ascending branches. The species sports 1½- to 3-inch-long, oval leaves that are a glossy dark green in summer and a rich yellow in fall. The bark is gray, not unlike that of I. vomitoria (yaupon holly), a feature that provides a soft color when the plant is hedged or trimmed into interesting shapes.

Possum haw grows natively in low areas, takes full sun to partial shade and, unlike many other deciduous hollies, thrives in alkaline soils. It can be used in the landscape as either a shrub or tree hedge from the Florida sands to the Midwest and far West. Hardy to Zone 5, it might survive even lower temperatures and is nearly windproof.

Depending on its habitat, possum haw grows in a shrub-like form reaching 8 feet tall and wide to a medium-size tree of 15 feet tall and 10 feet wide. Specimens in cultivation may reach 20 feet tall and 15 feet wide. Outstanding selections are found at the Missouri Botanical Garden in St. Louis and at Bernheim Arboretum and Research Forest in Clermont, Ky., near Louisville.

Male-flowering plants outnumber females almost 10 to 1, but only a scattering of males needs to be strategically positioned in a landscape to assure pollinating a host of fruiting females.

Dr. E.L. McWilliams, professor emeritus of horticulture at Texas A&M University in College Station, theorized that the principal distribution method of hollies in nature is through bird droppings; that would account for possum haw's habit of growing along fencerows.

The seeds (drupes) have a hard coating and must be scarified, as well as stratified, in moist sand or peat before they germinate. Even then, some may be delayed as long as three years. Semihardwood cuttings can be taken in summer or fall and treated with 1,000 to 3,000 parts per million IBA to obtain reasonable rooting percentages.

Possum haw has no serious pest problems.

Though cultivated since the 18th century, I. decidua has recently been rediscovered by growers who have developed various forms - from weeping to upright - and an array of new fruit colors. It should be noted that some cultivars found in literature have not been popularized due to their difficulty to propagate vegetatively. Possum haw has also found renewed favor with florists who find the branches useful in decorating, and the fruit persists for weeks.

For those who prefer deciduous plants and winter color, I. decidua is a good choice. With all the variations in form and color found in nature, more selections could be made.

Dr. David L. Morgan
Horticulturist
Bedford, TX
DavidLMorgan@sbcglobal.net