Viburnum trilobum, also known as Viburnum opulus var. americanum L. Ait
Some Other Common Names: American cranberrybush, guelder rose, dog rowan, *European cranberry tree, marsh alder, rose elder, red elder, water elder, dog elder, gatten tree, whitten tree, ople tree, snowball tree, crampbark
Introduction: The highbush cranberry is actually not a cranberry at all, though its fruit, or “drupes” as they are known taxonomically, strongly resemble cranberries in both appearance and taste. They also mature in the fall, as cranberries do. The two plants are quite different, however. Both are native to North America, but the highbush cranberry is a Viburnum, a member of the Caprifoliaceae, or Honeysuckle family, in contrast to the ‘true,’ or ‘lowbush’ cranberry, which is a Vaccinium, a member of the Ericaceae—Heather or Heath—family. The Honeysuckle family is comprised of about 400 species, with 11 tree species—and numerous shrub species—that are native to North America. They are located mostly in north temperate regions and in tropical mountains. In North America, the highbush cranberry stretches from British Columbia east to Newfoundland, south to Washington state and east to northern Virginia, with an isolated population in New Mexico. According to the Natural Resources Conservation Service, the highbush cranberry is listed as ‘endangered’ in Indiana, ‘threatened’ in Ohio, and ‘rare’ in Pennsylvania.
Plant Description: Considered a large and hardy deciduous shrub with a moderate growth rate of up to 3 ft. per year, the plant is typically 8 to 15 feet tall by 8 to 10 feet wide, with arching stems and a very dense, rounded form, making it a popular landscaping choice for use as a screening hedge [For a solid screen, plants should be spaced 2 to 3 ft. apart.]. It is noted for attracting wildlife, especially birds which benefit greatly from the fruit, which can remain on the branches well into mid winter. It is tolerant of frost, likes sun or semi-shade, and is successful in most soil types but does best in well-drained, moist soil that is rich and loamy. Established plants can tolerate drought, but they are helped by supplemental watering during such periods.
- Leaves: Opposite, simple, 3-lobed and 2 to 4 inches long. They are superficially similar to many maple leaves, but have a somewhat wrinkled surface and impressed venation. They are glossy dark green in the summer but often change to yellow-red or red-purple in the fall. The petiole is grooved and has round, raised glands near the base.
- Flowers: It produces flat-top clusters of showy white flowers in June. The clusters are 2 to 3 inches across, with an outer ring of larger, sterile flowers. Although the flowers are hermaphrodite (having both male and female organs) and are presumably self-fertile, there is some debate about that so it is probably best to grow at least two different cultivars in order to ensure fruit and fertile seed production. The flowers are also pollinated by insects.
- Fruit: Nearly round drupe (drupe: a fleshy fruit with a central stonelike core containing 1 or more seeds) about 1/3 inch diameter with a single large seed, bright red, juicy and quite acid, like a cranberry. The seeds ripen from August to September. It does not begin to produce fruit until approximately five years of age.
Edible Qualities: The fruits/drupes can be eaten raw (though not very tasty that way) or cooked, and like cranberries, they are rich in vitamin C and so have a tart, acid taste (the taste is best after a frost and when picked slightly under-ripe). They are an excellent substitute for cranberries and are likewise used in preserves, jams/jellies, sauces, etc., which make delicious condiments for meat and game. The jam reportedly has a very pleasant flavor.
NOTE: *There is also a European variety of highbush cranberry (Viburnum opulus) that is said to produce inedible fruit.
Insects: Reported to have very few insect problems in general, but one insect in particular—the Viburnum Leaf Beetle (Pyrrhalta viburni P.)—is capable of completely defoliating highbush cranberry stands (complete defoliation has been seen before in Maine–see photos below). Both the larvae and adults of the beetle feed on the leaves, severely skeletonizing them. The trees can survive this injury, however, and can go on to leaf out normally again the following year. Severe damage inflicted yearly, however, will kill the tree. The Viburnum leaf beetle was introduced from Europe, and in fact the first North American populations of the beetle were discovered on European highbush cranberry plantings in the Ottawa/Hull region of Canada. There are several fact sheets about the Viburnum leaf beetle on the web, including these by Cornell Cooperative Extension and UMass Extension:
LEFT: Highbush cranberry shrubs in central Maine defoliated by Viburnum leaf beetle larvae. RIGHT: Four Viburnum leaf beetle larvae feeding on one of the branches. With all of the leaves already consumed, these larvae were feeding on the bark and inner branch layers!
Photos by Charles Armstrong
Cranberry questions? Contact Charles Armstrong, Cranberry Professional. University of Maine Cooperative Extension || Pest Management Office || 491 College Avenue || Orono, ME 04473-1295 || Tel: (207) 581-2967 [email: email@example.com] If you are looking to purchase some highbush cranberry trees, I have had success myself with a particular source I found on the web and would be happy to share the details of my own experiences with anyone who asks.