Ask Mr. Smarty Plants

The University of Maine Cooperative Extension has some good news for you! Viburnum opulus var. americanum (Viburnum trilobum is an older name), called American cranberry bush or Highbush Cranberry, have an outer ring of large, sterile flowers and an extensive inner section of smaller flowers that are have both male and female flower parts. So they are self-fertile and will produce fruit (after they are pollinated by the wind or insects). The cranberry-like fruit which ripens in late summer is edible for humans and birds. Many other viburnums are not self-fertile and do need another blooming at the same time to cross pollinate and produce fruit.

Here’s what the University of Maine Cooperative Extension writes about Highbush Cranberry flowers and fruit. Also ask your nursery if there are problems with Viburnum leaf beetle (Pyrrhalta viburni) in your area before you purchase your new shrub.

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. The flowers are hermaphrodite (having both male and female organs) and are therefore self-fertile, meaning that an individual plant’s flowers can pollinate one another, so there is no need for a second type (or even a second individual plant) to provide pollen and produce fruit. The flowers are pollinated by both wind and insects.

Fruit: Nearly round drupe (drupe: a fleshy fruit with a central stonelike core containing one 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. ‘Wentworth’, ‘Andrews’, and ‘Hahs’ are three varieties that are examples of the better-tasting, American type.

Note: *There is also a European variety of highbush cranberry (Viburnum opulus) that is described as having inedible/bitter fruit. If you wish to eat the fruit, make sure you plant the true North American species, Viburnum opulus var. americana. You will often see it for sale under its old name, Viburnum trilobum, but keep in mind that although a nursery may list it as americana or trilobum, many people have had the unfortunate experience of discovering that what they ended up with was nevertheless the European variety. It may also be worth noting that the European form (V. opulus) is widely naturalized in central Maine, and a trusted source has written to say that he finds that one - at least in central Maine – more often than he finds the native (trilobum/var. americana) form!