As Thanksgiving draws near, cranberries are on the menu for many American feasts. Vaccinium macrocarpon, known as the American or large cranberry, is the well-known fruit commonly grown in bogs or man-made sandy beds in states such as Wisconsin, Massachusetts, Oregon, Washington, and New Jersey. American cranberries are produced on low-growing, trailing vines which thrive at pH levels between 4.5 and 5.0. Most American cranberries are harvested by flooding the bog in late September through October. The fruit floats to the water's surface and then is harvested by specialized machinery and transported to processing facilities. Eventually, this is the fruit that winds up on dinnerplates at Thanksgiving or is consumed as dried fruit, sauce, or juice.
Soil and climatic conditions in Missouri are not suitable for growing American cranberry. Although not a true cranberry, highbush cranberry, also known as American cranberrybush (Viburnum opulus var. americanum) can be grown as an alternative fruit for American cranberry (Figure 1). Highbush cranberry also has ornamental value in the landscape with showy white flowers, red fruit, and colorful fall foliage. This plant also provides wildlife food and provides cover for small mammals and birds, including ruffed grouse. However, its fruit is eaten only sparingly by pheasants and some songbirds.Figure 1 Bright red drupes on a Viburnum opulus shrub.
Highbush cranberry is a deciduous shrub that grows to about fifteen feet in height. Plants can be grown in part shade, but produce more fruit of higher quality in full sun. Also, these shrubs are adaptable to a wide range of soils, but perform best in a well-drained site. Plants require pruning when branches become crowded to maintain good fruit production. Thinning cuts, where old large stems are removed at the base of the plant, can improve fruiting. To maintain plants as ornamentals with a more compact growth habit, prune them annually just after flowering.
In April to May, highbush cranberry shrubs produce a white, flat inflorescence composed of fertile flowers in the center and an outer ring of larger, showy, sterile flowers (Figure 2). This type of inflorescence is frequently called a lacecap. The fruit resembles that of the American cranberry in size and color, but is generally more translucent when it ripens in September and October. Cross-pollination is not required for fruit set.Figure 2 The lacecap Inflorescence of a highbush cranberry with fertile flowers in the center and an outer ring of large sterile flowers.
Improved cultivars of highbush cranberry that produce superior fruit include Andrews, Hahs, Hogg's Red, Manitou, Phillips, and Wentworth. Typically, these cultivars begin to produce fruit during the fifth growing season. The cultivar, Compactum grows to only about half as tall as non-dwarf types. Like the tart American cranberry, fruit is best used processed into jelly, juice, sauce, or a condiment for meat or game.
Although pests are generally not problematic, the viburnum leaf beetle (Pyrrhalta viburni) can defoliate highbush cranberry shrubs. Larvae usually begin feeding on the lower leaves of the shrub, leaving only the main veins intact. Later, adults once again feed on the leaves, first creating irregularly-shaped holes in the foliage, but they can eventually defoliate or kill the shrub in severe cases. Recommendations for the control of this pest can be found at: http://idl.entomology.cornell.edu/wp-content/uploads/Viburnum-Leaf-Beetle.pdf. Occasionally, other insects, such as tarnished plant bugs, stem borers, or thrips may damage highbush cranberry shrubs. Additionally, bacterial leaf spot, powdery mildew, and shoot blight diseases may be found after periods of extended rainfall.
When purchasing highbush cranberry plants, obtain them from a reputable source that clearly identifies the Latin name of the plant (Viburnum opulus var. americanum). A related type, known as European cranberrybush, (Viburnum opulus) is considered weedy and potentially invasive by the Missouri Botanical Garden. Thus, European cranberrybush is not recommended for planting. European cranberry bush plants are similar in appearance to that of highbush cranberry, but differ in the structure of glands found at the base of leaf petioles. Photographs of these glands can be found at: https://extension.umaine.edu/cranberries/highbush-cranberry/. Also, the fruit of European cranberrybush has very large seeds and is very astringent with high acidity and is often infested with aphids.
REVISED: October 26, 2021