Winterberry holly delivers color to a garden in both fall and winter
It may come as a surprise to many people that there are hollies that not only drop their leaves in advance of winter but become stunning landscape plants in the process.
I am thinking of the winterberry holly, a big and showy native shrub that has spawned a handful of even lovelier varieties.
Its clusters of red berries begin to color in September, but they are barely noticed because of the abundant green foliage (without prickles). By October, the leaves have turned a golden yellow and the pairing of fall color and plump red berries is a cherished moment in the garden. For a month now, the twiggy canopy has been bare of leaves to reveal a mantle of hundreds, even thousands of exposed, eye-catching red berries.
If the plant is well placed, not crowded by others and given its own stage, it captures the low winter sun and just dazzles. On a larger property, I would place a mass of it at the far end of a lawn, ideally against a screen of mature evergreens to set off the berry display.
The winterberry is planted as an upright twiggy plant, but after a few years it spreads into an oval-shaped, multi-stemmed shrub. It has a tendency to sucker if let alone, but the artful gardener can cut away suckers and internal branches, and train the plant into a specimen with its lower and smooth brown-gray stems exposed and open. It gets about eight feet tall with a similar spread, so it needs some room.
With a field of snow in front of it, a clump captures the season in stunning fashion. The winterberry is among holly species that individually produce either male or female flowers. Only the female plants set fruit, and only in the proximity of a male. There are about 40 named varieties of the winterberry, including Scarlett O'Hara, selected for its heavy fruit set and more upright habit. Her suitor, you will have guessed, is a variety named Rhett Butler, though other male varieties would work as well, and the list includes Southern Gentleman, Jackson and Jim Dandy. Rhett, you've got some competition. And you need only one male plant for as many as 10 or more females.
The birth of Sparkleberry
In the early 1960s, which is the day before yesterday in the world of plant breeding, hybridizers at the U.S. National Arboretum took a Japanese species of the winterberry (grown from seed collected in the wild in Japan) and crossed it with the native one. As is sometimes the case, the sum was greater than its parts. The offspring, which they named Sparkleberry, had bigger, brighter fruit than its parents, the berries stay on the branches longer, and the plant has more all-around vigor, growing 12 feet tall or higher. The breeders also hybridized a male, Apollo, whose flowers appear at the same time as Sparkleberry's, assuring optimum pollination and fruit set. It, too, is a large shrub, so the pair would probably not be a good choice for a small rowhouse garden.
However, a dwarf selection of the native winterberry named Red Sprite matures at four feet and would pair well with Jim Dandy, which gets to only five feet and blooms about the same time.
The winterberry is a lowland plant that takes periods of both drought and standing water and is perfect for spacious damp areas as long as the soil is on the acidic side. If the soil is too sweet, holly leaves are likely to turn yellow from iron deficiency. The pH can be lowered by adding aluminum sulfate or organic fertilizer formulated for hollies.
The winterberry also makes a fabulous cut branch for arrangements, and growers have raised whole orchards to supply the florists' market, using such varieties as Maryland Beauty, Christmas Gem and, increasingly over the years, the large-berried Winter Red. In the garden, the plant provides food for the birds as the winter progresses.
The display can be hit-or-miss from one year to the next, much of it depending on whether we have lots of rain in May, when the hollies flower. That's because too many spring showers keep pollinators grounded.
A specimen of Scarlett O'Hara at Green Spring Gardens near Alexandria looks as good as anyone would want, a beacon from across the central lawn. At the National Arboretum this year, original display plantings of winterberry varieties, including Sparkleberry, show sporadic fruiting and early aging of the fruit. Some specimens remain showy, though, including a Winter Red that is now 10 by 15 feet.
By the entrance to the arboretum bonsai pavilion, three beautifully pruned specimens of another native and Japanese winterberry cross, Harvest Red, are festooned with small but abundant red fruit. The stems form a tracery against the cream stucco wall, and the berries gleam in the blue winter sky.