By Ann Marie VanDerZanden
Associate Professor of Horticulture
Iowa State University
There are more than 150 species and cultivars of viburnums. With this many to choose from there is bound to be one or more that fit perfectly in your garden. In addition to beautiful aesthetics, viburnums are adaptable to wet or dry soil and can handle full sun to full shade. Once established most viburnums are drought resistant and require minimal maintenance. An additional feature is that they have very few disease or insect problems, especially in Iowa.
The range of aesthetic characteristics that viburnums display is a gardener’s delight. You can choose plants that are evergreen, semi-evergreen or deciduous. Some species are under two feet in stature while others are towering 20 footers. Viburnum leaves can be rounded or lance-shape, smooth, velvety or rough, and often deeply veined to give the leaf an undulating appearance. The often fragrant flowers are white or pink, and most species bloom between early spring and early summer. The fruit (drupes) set in the late summer are metallic blue, bright red and in some species change from red to deep purple as autumn progresses. The fall color on the deciduous types is equally striking ranging from bright clear yellow, to brilliant crimson, to a deep rusty maroon.
To help focus your plant selection I have divided some of the best performing viburnums for our climate into two size categories; large shrubs (over 12 feet tall) and medium shrubs (6-10 feet tall). In some cases I have also listed cultivars that have a smaller and more compact growth habit. As you think about locating these plants in your landscape it is helpful to know that most viburnums have a mature spread that is equal to their height.
The Wayfaringtree viburnum (Viburnum lantana) grows into a large shrub or small tree reaching 10-15 feet in height and spread. Large white flat-topped blossoms in mid-May give way to red drupes in mid-summer. By late summer, the drupes turn to a deep purplish-black and they will persist on the plant through autumn. The large, dark green, leathery leaves give this plant a coarse texture and can make it an interesting focal point in a shrub border. The leaves take on a purplish-red color in the fall and often last into early winter. The cultivar ‘Mohican’ (V. lantana ‘Mohican’) has a more compact growth habit (6 feet tall; 6-8 feet wide), making it ideal as a hedge plant or for a smaller garden.
If you have a large garden or acreage, consider the Nannyberry Viburnum (Viburnum lentago). This species is one of the largest viburnums (20 feet tall, 10 feet wide) and is a durable and adaptable native that provides excellent winter food for a variety of birds.
For dry sites consider Viburnum prunifolium, the Blackhaw viburnum. It grows to 12-15 feet tall and 8-12 feet wide, produces a profusion of dark blue drupes, and can be a good substitute for a crabapple tree if pruned to a single trunk.
Viburnum opulus, the European cranberrybush viburnum, is a showstopper in the spring. The plant reaches 6-10 feet in height with a spread of 10-15 feet. In mid-spring it is covered with softball sized white blooms. The cultivar ‘Roseum’ is similar except that the blooms have a subtle pink hue to them. The flowers are followed by a showy display of red fruit and yellow-red fall color. This species looks great when it is pruned into a beautiful vase shaped large shrub.
The Arrowwood viburnum (Viburnum dentatum) is a fast-growing viburnum with a slightly suckering habit. This species reaches 6-8 feet with a similar spread. It blooms from May to early June and bluish-black drupes (fruit) develop from September to October. The summer and fall foliage are attractive. This species is adaptable to full sun or partial shade and many soil types including alkaline soils.Arrowwood viburnum makes an excellent unclipped hedge against which showy perennials and annuals can be displayed.
Arrowwood viburnum cultivars to look for include Bluemuffin® (V. dentatum ‘Christom’) and Autumn Jazz® (V. dentatum ‘Ralph Senior’). Bluemuffin® is a compact form reaching 5-7 feet tall and 4-6 feet wide. Autumn Jazz® is aptly named because of its superb range of fall color including yellow, orange, red and burgundy.
Another native viburnum that provides food for wildlife is Viburnum trilobum, the American Cranberrybush viburnum. The species can be used individually as a specimen plant or in mass to create a large hedge (10-12 feet tall and wide). The distinctive 3-lobed (trilobum) foliage has a reddish tint in the spring, while summer leaves are a beautiful glossy green, and autumn color is often a reddish-purple. Round white blossoms 3-4 inches across open in mid to late May. In the fall bright red clusters of pea sized, fleshy drupes develop. These beautiful clusters can last well into February if the birds don’t eat them first. The result can be a striking contrast against the bright white winter snow.
Several cultivars are available. If space is limited, consider ‘Bailey Compact’ or ‘Alfredo,’ both of which grow to 5-6 feet tall and wide. Another cultivar to consider is Red Wing® (V. trilobum ‘J.N. Select’) which reaches 8-10 feet tall and 6-8 feet wide. The new growth on Red Wing is particularly striking since it is a deep red color.
Ann Marie VanDerZanden, Horticulture, (515) 294-5075, firstname.lastname@example.org