Highbush Cranberry: Viburnum Versus Vaccinium

From Extension Collaborative Wiki

Introduction

The highbush cranberry (Viburnum trilobum or Viburnum opulus var. americanum L. Ait) 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 kind of 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 Federal agency that works in partnership with the American people to conserve and sustain natural resources--the highbush cranberry is listed as endangered in Indiana, threatened in Ohio, and rare in Pennsylvania.

Highbush Cranberry 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.^[1] 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: Flat-top clusters of showy white flowers are produced in June. The clusters are 2 to 3 inches across, with an outer ring of larger, sterile flowers. Although the flowers are hermaphrodite^[2] and are thus 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^[3] 1/3 inch in 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 of Highbush Cranberry

The fruits/drupes can be eaten^[4] raw 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, sauces, etc., which make delicious condiments for meat and game. The jam is said to have a very pleasant flavor.

Insect Pests of Highbush Cranberry

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 (as seen at a location in Maine in 2005--see photo below). It is primarily the larval stage of the beetle that feeds on the leaves^[5], severely skeletonizing them. The trees can survive this injury, however, and go on to leaf out normally again the following year, which is also true in the situation observed in the photo below. Severe damage inflicted yearly, however, has been reported to kill the tree. The Viburnum leaf beetle was introduced from Europe, and in fact the first North American breeding 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 one by Cornell Cooperative Extension --> Viburnum Leaf Beetle.

Viburnum Leaf Beetle larvae feeding on a highbush cranberry branch in central Maine, just east of Bangor. All of the leaves had already been eaten!

Other Common Names for Highbush Cranberry

1. American cranberrybush
2. guelder rose
3. dog rowan
4. European cranberry tree
5. marsh alder
6. rose elder
7. red elder
8. water elder
9. dog elder
10. gatten tree
11. whitten tree
12. ople tree
13. snowball tree
14. crampbark

NOTES

1. ↑ For a solid screen, plants should be spaced 2 to 3 ft. apart.
2. ↑ Hermaphrodite: having both male and female organs
3. ↑ Drupe: a fleshy fruit with a central stonelike core containing 1 or more seeds
4. ↑ There is also a European variety of highbush cranberry (Viburnum opulus) that is said to produce inedible fruit.
5. ↑ Viburnum Leaf Beetle adults also feed on the leaves.