Viburnums Merit A Place in the Sun
Viburnum, that delightful garden shrub, bears a Latin name meaning the wayfaring tree, but one wonders if it has been left a bit by the wayside.
It is a shrub that shines in the spring, flowering for weeks in its various forms, some of the blooms highly fragrant. Its second season is in autumn when the plant is festooned with fruit and beginning to exhibit fabulous fall leaf color.
Michael Dirr, America's tree and shrub guru, once proclaimed that "a garden without a viburnum is akin to life without music and art."
I'm thinking a lot about viburnums these days, not just because fall is one of the cherished seasons of the plant, nor because the half-dozen types in my garden are faring reasonably well in the drought. It comes to mind because Dirr is once more championing a plant that serves so many roles and yet remains underused and undervalued. Dirr's new book, "Viburnums," is published by Timber Press and costs $39.95.
The reason this shrub is so versatile is that it is not one plant, but a range of species and their variants that offer an attractive solution to almost any landscape problem.
Heady fragrance? The Burkwood and Korean spice viburnums. Fall color and fruit? The southern blackhaw and smooth witherod viburnums. Tall accent shrub? The Chindo viburnum. Screening out the neighbors? The leatherleaf viburnum.
Although the viburnum steps forward in the spring and fall, the summer foliage is often superb -- clean, green, heavily textured and largely untroubled by pests and diseases. Once established after a year or two, viburnums are not as fussy as such other shrubs as azaleas, pieris, hydrangeas or mountain laurels. Some of the fall fruiting kinds need a second plant for cross-pollination and good berry set.
If viburnums have a drawback, or perceived drawback, it's that they tend to get too large for today's smaller lots. This bulk is a plus, in my book, because viburnums can be used as building blocks in plant borders, providing background form that, after flowering, steps back to allow other shrubs and perennials to shine as the season advances. In small to mid-size gardens where the owners are blessed with a little patience, certain varieties also provide the perfect scale of screening. One thinks of the southern blackhaw, growing to 10 feet or more; the leatherleaf, another 10-footer; and the Prague viburnum, at least eight feet high.
Some have become old hat; the Korean spice and the Chinese snowball viburnums come to mind. But what is remarkable about the plant is how many newer varieties are so little known and out of the mainstream loop of consumer use and retail supply.
"There is a future for these things, but we have to get the growers up to snuff," Dirr said in an interview. Large growers may be producing half a million clones of the wildly popular hydrangea Endless Summer, which Dirr discovered, "but they aren't going to roll the dice on a viburnum that doesn't get any marketing," he said.
"New" is a relative term in shrub breeding, and we're talking about varieties that have been in the works since the 1950s. Many of these improved viburnums trace their origins to one man, Donald Egolf. Egolf, who died in 1990, was a plant hybridizer at the National Arboretum who is perhaps best known for bringing the world the Natchez crape myrtle. He devoted most of his career, however, to the methodical and patient development of viburnums.
His towering viburnum triumph is the Shasta, a doublefile variety developed for its broad horizontal habit. In Egolf's version, the showy white lacecap flowers, borne aloft the sideways stems, are made even showier. Shasta is a large shrub, six to eight feet tall but 10 feet wide at maturity. It provides a layered look so valuable in garden plants, which want to grow vertically, by and large. Shasta gets taller with great age than first billed, Dirr said, but remains a "tremendous" ornamental shrub.