European cranberry bush (Viburnum opulus)
Nonnative:
VIBURNUM. Family: Elderberry (Adoxaceae). Genus: Viburnum. EUROPEAN CRANBERRY BUSH, EUROPEAN HIGHBUSH CRANBERRY, COMMON SNOWBALL VIBURNUM, CRANBERRY VIBURNUM, GUELDER ROSE (V. opulus; V. opulus subsp. opulus, syn. V. opulus var. opulus). Origin: Eurasia. Height/Spread: 8–15 feet. Ornamental Attributes: Large flat-topped clusters of white flowers in May. Its red fruit remind some people of cranberries; unreliable reddish-purple fall color. Identification Note: Viburnums are difficult to distinguish from each other. The glands of the leaf petioles of the European’s are cup-shaped while the glands of the American’s [see native alternatives] are columnar in shape and the fruit is “considerably more palatable.”80 Cultivation: Full sun best; moist to medium soil; naturalizes; susceptible to disfiguring aphids. Ecological Threat: Invasive in midwestern states. It interbreeds with the native highbush cranberry, creating hybrids that alter the gene pool of the native species. Cultivar Note: The invasive European cranberry bush has many hybrids and cultivars; they are also invasive.81 Zones: 3–8; BUDDLEJALEAF VIBURNUM (V. buddleifolium). Height: 8–10 feet. Ecological Threat: Naturalized in Ohio. Zones: 6–9; JAPANESE SNOWBALL VIBURNUM, DOUBLEFILE VIBURNUM (V. plicatum). Origin: China, Japan. Height/Spread: 13 feet. Looks like the native mapleleaf and possumhaw viburnums. Ecological Threat: Naturalized in midwestern states. Zone: 5; KOREAN SPICE VIBURNUM (V. carlesii). Origin: Korea, Japan. Height/Spread: 4–6 feet. Ornamental Attributes: Fragrant semisnowball-like flowers in April to May. Unspectacular fall color. Ecological Threat: Naturalized in Ohio. Zones: 5–7; LANTANAPHYLLUM VIBURNUM (Viburnum × rhytidophylloides): Has its own hybrids and cultivars. Ecological Threat: Invasive in Ohio. Zones: 5–8; LEATHERLEAF ARROWWOOD (V. rhytidophyllum). Origin: China. Height/Spread: 6–10 feet. Cultivation: Best in protected location. Ecological Threat: Naturalized in midwestern states. Zones: 5–8; SIEBOLD’S ARROWWOOD (V. sieboldii). Ecological Threat: Naturalized in midwestern states. Zones: 4–8; WAYFARING TREE (V. lantana). Origin: Europe, Asia. Height/Spread: 10–5 feet. Ecological Threat: Naturalized in midwestern states. Zones: 4–8.
Native Alternatives:
VIBURNUM. Family: Elderberry (Adoxaceae). Genus: Viburnum. Viburnum Ornamental Attributes: “Viburnums are treasured for their long season of interest: spring flowers, summer berries and colorful fall foliage.”82 The native species have dramatic branching structures, are adaptable, easily grown, and easily pruned to create dense hedges, and are “well-known for their splendid fall color, most of which are some shade of red.”83 For reliable heavy fruiting, plant at least 2 plants of the same species near each other. AMERICAN CRANBERRYBUSH, HIGHBUSH CRANBERRY (V. opulus var. americanum; V. trilobum). Height/Spread: 8–12 feet. Ornamental Attributes: Large showy white sterile flowers surround tiny white fertile flowers; maple-shaped leaves turn scarlet in fall; red fruit ripens in September and persists through February. Cultivation: Sun, part shade; dry, medium, moist, or wet soil; disease and pest resistant. Neither spreads nor creates thickets; easily pruned to create a dense hedge. Note: Endangered or threatened in parts of the Midwest. Zones: 2–7; ARROWWOOD VIBURNUM, SOUTHERN ARROWWOOD (V. dentatum var. dentatum). Height/Spread: 6–10 feet. Occasionally grows 20–25 feet as a small tree. Ornamental Attributes: White lace cap flowers, clusters of late August- to November-ripening blue-black fruit whose easy-to-eat small size and high fat content make them a preferred migrating and songbird food; brilliant red fall color. Cultivation: Sun best for flowers, takes part shade, most soils. Tolerant of black walnut tree toxicity. Note: Endangered, threatened, or rare in parts of the Midwest. Zones: 2–7; BLACKHAW (V. prunifolium). Height: 12–15 feet. Spread: 8–12 feet. Large shrub or small tree with horizontal branching. “Blackhaw is probably the most common viburnum in the Midwest.”84 Ornamental Attributes: Clusters of white flowers. “Rather a constant and pretty bloomer from April until June . . . the bluish-black drupes are covered with a bloom, and are agreeably sweet and good to eat. In the autumn the foliage turns to orange and purple” 85 (see p. 265). “This is another beautiful native that has aesthetic value year-round.”86 “Exceptionally ornamental but also easy care.”87 Recommended by Christopher Starbuck as an uncommon tree for specimen planting. Cultivation: Full sun best for flowers; takes deep shade. Moist to dry; tolerates wet soil, takes poor soil; drought resistant and tolerant of black walnut tree toxicity. Historical Note: In 1739, Peter Collinson thanked John Bartram for sending him a blackhaw. In 1771, Thomas Jefferson planted a blackhaw at Monticello. Zones: 3–9; DOWNY ARROWWOOD (V. rafinesqueanum). Height/Spread: 4–6 feet. Ornamental Attributes: White flowers in May to June. Bright red to burgundy fall color. “From the reddish-tinted new leaves in the spring, to the beautiful fall color that can begin in August while the black fruits are present, this is a species worthy of recognition,” write Weeks and Weeks.88 Cultivation: Full sun to shade, well-drained soil, tolerates drought. Note: Threatened in Kentucky. Zones: 2–7; MAPLELEAF VIBURNUM (V. acerifolium). Height: 4–6 feet. Spread: 3–4 feet. Ornamental Attributes: Pink buds become flat white flowers in May. Spring leaves have a reddish blush. In fall, the maple leaf–shaped green leaves turn pink to dark burgundy, contrasting with the shiny black fruit. “Mapleleaf viburnum is one of our more common viburnums that is underrated as an ornamental,” write Weeks and Weeks.89 Cultivation: Shade or half-day sun; an understory shrub of well-drained to dry soils. Tolerates black walnut tree toxicity. Zones: 4–8; NANNYBERRY (V. lentago). Height: 15–20 feet. Spread: 10–15 feet. Understory shrub or small tree of moist woods. Ornamental Attributes: Dense clusters of showy white flowers in May; drooping clusters of large black fruits in fall persist into winter; orange pedicels; known for its exceptional maroon fall color. Cultivation: Full sun to part shade, medium soil. Zones: 2–7; POSSUMHAW, POSSUMHAW VIBURNUM (V. nudum var. nudum). Confusion Note: Possumhaw is also the common name for POSSUMHAW HOLLY (Ilex decidua); see Fall Shrubs, p. 237. Height/Spread: 5–12 feet. Ornamental Attributes: Showy white flowers. Fruits turn multiple colors before becoming showy blue or blue-black. Smooth, lustrous, lightly leathery foliage consistently turns purple and red. Cultivation: Prefers more sun than shade, moderately fertile, well-drained moist soil. Note: Endangered in Kentucky. Zones: 5–9; RUSTY BLACKHAW, SOUTHERN BLACKHAW, BLUE HAW (V. rufidulum). Height: 15–25 feet. Ornamental Attributes: Dark, rusty-colored buds, very large white flower clusters, brilliant red fall color, dark blocky bark. “Simply gorgeous any time of the year.”90 Tolerates black walnut tree toxicity. Zones: 5–8; SQUASHBERRY, MOOSEWOOD VIBURNUM, LOWBUSH CRANBERRY (V. edule). Height: 2–7 feet. Ornamental Attributes: A northern