I've been a fan of viburnums for some years now – they have beautiful flowers, good looking foliage and great fall color. They also have berries that the birds eat. On top of good looks, they are truly some of the most versatile shrubs that I know. I like to say there is a native viburnum to suit every situation you have: sun, shade, wet, or dry. Yes, the blooms all look very similar but there is a difference in foliage shape, berries, size and habit.
It would be hard to pick a favorite but Viburnum acerifolium would certainly be on the short list. Commonly known as the mapleleaf viburnum because of the leaf shape, the first blog entry that I ever wrote was about this plant, so I’ll be brief here (and you can read more about it there). The range of this plant in Georgia is primarily in the more northern regions, but it does extend into the upper coastal plain. Found in the understory of mesic woods (moderately moist), it is tolerant of drier and shadier conditions than many shrubs. It tends to sucker a bit, creating a loose colony in ideal conditions. The fall color is superb, and the berries are dark blue and large.
|Viburnum dentatum 'Blue Muffin'|
The viburnums known as “arrowwoods” (for their straight limbs) include Viburnum dentatum (southern arrowwood) and Viburnum recognitum (northern arrowwood). More unusual are two others: bracted arrowwood, Viburnum bracteatum, and downy arrowwood, Viburnum rafinesqueanum, both of which are occasionally found in the Piedmont. V. dentatum is found throughout Georgia from the northernmost counties into the coastal plain, including a few of the maritime counties. Growing conditions vary from upland sites to swampy tracts. A few cultivars are now available in nurseries: ‘Blue Muffin’ is one that I have and I hope they didn’t mean for “muffin” to indicate a dwarf form because it is not. According to Michael Dirr, ‘Little Joe’ is a true dwarf in his Georgia garden. Berries are smallish and medium blue in color.
|Viburnum nudum var. cassinoides|
Another wet tolerant viburnum is possumhaw or Viburnum nudum, a species which now includes Viburnum nudum var. cassinoides . Between the two of them, this species can be found in practically the entire state, including the maritime areas. While there are many similarities between the two, notably their bare twigs and their fruit, I find that the foliage is quite different. Smooth, dull green leaves with a faint white stripe down the center are characteristic of var. cassinoides while nudum has shiny, deep green leaves that have no stripe and are faintly “quilted” in appearance. Both have excellent fall color and pinkish berries that are colorful enough to resemble flowers from a distance. In swampy conditions, suckering is part of the habit. Several cultivars have been developed, and one of the best known is 'Winterthur'.
One viburnum that has been getting more use in the garden is the small leaf viburnum, Viburnum obovatum. A favorite cultivar in the trade is ‘Reifler’s Dwarf’ which offers compact growth, shiny green leaves and dozens of flowers when grown in full sun. For me it has been semi-evergreen, another bonus. An even more compact form is ‘Mrs. Schiller’s Delight.’ The species is indigenous to the coastal plain but does well in Piedmont areas.
Even though viburnums are shrubs, some of them can get quite tall, and there are even two of them that can be considered as small trees. Viburnum prunifolium is known as blackhaw viburnum and the very similar looking Viburnum rufidulum is known as rusty blackhaw. The differences between them are slight, but noticeable if you are looking for them, especially in the winter when the rust- colored leaf buds of Viburnum rufidulum are present. The leaves of blackhaw are rather dull and thin compared to the shiny, leathery leaves of rusty blackhaw. Both species grow to over 20 feet at maturity. They both make fine small trees in the garden. The distribution of the two varies – blackhaw is more northern while rusty blackhaw is widely distributed throughout the state.
One viburnum that is not native to Georgia is the one known as American cranberry bush: Viburnum opulus L. var. americanum or formerly Viburnum trilobum. I have seen this for sale in Georgia stores, but it is a plant that normally grows quite a bit north of us.
I hope that the next time you are considering a shrub for your yard that you will give viburnums a closer look. Their late spring flowers will delight you and insects alike; come fall the rich colors will delight you again.
Good reference: Michael Dirr’s book Viburnums, published in 2007. While it includes non-native viburnums, the pictures of flower, fruit, foliage and habit for each species make this an excellent resource. It is especially good for Georgia gardeners as he includes comments about ones that he has grown in Athens, GA.