Viburnum shrubs, in their great diversity, for the most part grow trouble-free in the garden according to American woody plant expert Michael Dirr of the University of Georgia. Poor growing conditions, such as soggy soil or inadequate light, lead to problems with insects and diseases, however. A rich and moist soil with organic matter and ample air circulation around shrubs helps reduce foliage diseases, and insect populations fluctuate annually.
Dirr cites three diseases specific to viburnums, although they rarely are devestating. Botryosphaeria canker, downy mildew and powdery mildew are fungal diseases. The aforementioned canker occurs most frequently during periods of drought. Bacterial leaf spot occurs on older, lowermost leaves on the plant, and occasionally bouts with crown gall, rust, spot anthracnose and verticillium wilt may appear on viburnums. Overall, Dirr states, gardeners don't need to worry about diseases on viburnum shrubs like they would on their roses.
Minor, seasonal troubles occasionally arise on viburnum leaves or flowers from scales, thrips, Asiatic garden beetle, Japanese beetle, dogwood twig borer, potato flea beetle, tarnished plant bug and the citrus flatid planthopper. The "A-Z Encylopedia of Garden Plants" also mentions tree hoppers, mealybugs and aphids as problems on viburnums at times. Dirr sounds a warning about the viburnum beetle, a native of Europe that has been spreading across the eastern United States since in middle and late 20th century. There is considerable variability of susceptiblity among the many viburnum species; the most vulnerable species die within 2 to 3 years after infestation. Dirr also states that shrubs grown in shadier garden situations receive more leaf feeding damage from the viburnum beetle in his observations.
While viburnums aren't typically browsed on by hungry deer, which choose to eat other favourite tasty garden buds and leaves first, a hungry deer may chomp on viburnum. Dirr comments that any shrub with the species Viburnum utile or Viburnum carlesii as genetic parents are not eaten by deer, but others, especially Viburnum opulus, are. The damage done by deer depends on region and climate as well as other localised, seasonal events that cause some plants to be eaten one year but not the next.
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