Osmaronia: Oso Berry
West of the Cascades, our native Oso Berry is a true herald of spring. This small tree, or multi-stemmed shrub, is a common understory plant in open forests, with small racemes of white flowers appearing anywhere from February to April.
Plant care & info
Family: Rosaceae
Genus: Osmaronia or Oemlaria
Common Name: Indian Plum, Oso Berry
West of the Cascades, in moist to dry wooded settings at low elevation, from southern British Columbia to southern California.
Drooping clusters of small white flowers in early spring, blooming as leaves are emerging. Leaves are large and elliptical. On the female plants, small fruits hang down in groups from slender stems, turning from red to blue-black.
Can sometimes tolerate full sun, but prefers a mix of sun/shade, or all day dappled sun. Moist to dry conditions.
Virtually pest and disease free.
It provides a welcome nectar source for hummingbirds and early pollinators, like our also native Orchard Mason Bees. But please don’t be tempted to cut a stem of these lovely little flowers to bring indoors; the smell has been likened to that of cat urine. Best to enjoy from a small distance and let the hummers and bees have their fill.
The leaves that follow the flowers are large and elliptical, and when crushed give off a scent similar to cucumber, much better than the flowers.
Unlike others in the Rose family, Osmaronia is dioecious – male and female flowers occur on separate plants – and so you would need both to obtain the “plum” of its common name. To the knowing eye, the difference between the male and female flowers can be observed; however most of the time the plants available in nurseries aren’t labeled as to gender (but they tend to be male).
The fruit is small, with a relatively large pit, and opinion varies widely as to its palatability. This may help explain why more of them aren’t in commercial production. But, if you do happen to find yourself with a producing female Indian Plum, you will be rewarded with birds that will be attracted to your garden, for many bird species find the summertime fruit very much to their liking.
Osmaronia is a relatively fast growing shrub – or tree, if it is pruned to a single trunk. Its tendency is to sucker into a multi-stem shrub – growing to about 10’ to 15’ tall and 12’ or more wide. Its growth is more open than dense. It prefers dappled sun or a nice mix of sun/shade, though it will grow with more or less of both.
Amenable to conditions both moist and dry, it is an excellent choice to plant in the drier conditions beneath conifers. Once established it only occasionally needs supplemental water, and is reputedly pest and disease free.
All this makes it a great, low-maintenance and trouble-free candidate for the woodland and/or bird attracting garden.
Find Natives for your garden
We offer a great selection of Northwest Natives from spring through fall. The plants featured are highlighted favorites, but they do not represent ALL of the plants we carry. For a more complete list, see our Northwest Native Plant List.
