Plant Talk: Giving Buffaloberry its Due
- susan5383
- Apr 22
- 8 min read
By Kate Wilson
Do buffaloberries elude notice by gardeners and native plant growers? A 2002 bulletin by the Cereal and Oilseed Research Centre of Agriculture and Agri-Food Canada may offer a clue, with its title Poorly Known Economic Plants of Canada (1).
Yet buffaloberries are excellent nitrogen fixers, an important food source for wildlife, and can thrive even in rocky, hardscrabble soils. They are hardy perennials that have their own unique beauty. Maybe it’s time to elevate these native shrubs’ profiles in the horticultural and even agricultural worlds.
Buffaloberries are shrubs of the Elaeagnaceae (Oleaster) family within the Shepherdia genus. The two species that show up in central Alberta are Canada buffaloberry (Shepherdia canadensis) and silver buffaloberry (Shepherdia argentea). A third, Shepherdia rotundifolia, is endemic to the Colorado Plateau in the western U.S. Another member of the Elaeagnaceae family, sea buckthorn (Hippophae rhamnoides), is a non-native shrub planted in Edmonton (particularly along road medians) and has escaped into the river valley. It may be confused with silver buffaloberry because of its similar grey leaves, although its berries are distinctively yellow!
Widespread species have many names!
Shepherdia was so-named for British botanist John Shepherd, curator at the Liverpool Botanic Garden in England from 1802 to 1836. Canadensis means relating to Canada, and argentea is Latin for "silvery".
Canada buffaloberry, is also known as russet buffaloberry due to the rust-coloured branches, as well as soopolallie, a mixed-language name that arose with the Chinook peoples of present-day Washington and Oregon, because of its ability to generate a soap-like lather due to its saponin content. Silver buffaloberry – named for its silver-green leaves – is also called thorny buffaloberry. It is not to be confused with silverberry (or wolf willow, Elaeagnus commutata), a separate genus of the Elaeagnaceae family, which has similar grey leaves.
The name buffaloberry likely developed from the practice of Plains First Nations in using the berries with bison meat. French names are shépherdie du Canada or grains de boeuf, seemingly an allusion to buffalo, and shépherdie argentée.
Distribution and habitat
The Shepherdia genus is endemic to North America. Canada buffaloberry ranges across Canada and the northern US, and follows the Rocky Mountains south to Arizona and New Mexico. It reaches its northern limits north of the Arctic Circle and has been reported at elevations up to 1,600 m in Alberta and 2,500 m in Idaho.
Silver buffaloberry is a more southern species, native to the aspen parkland and grasslands of the Prairie Provinces and the Great Plains, as far south as New Mexico and east to Oklahoma.
Canada buffaloberry typically grows in partial shade within a wide range of habitats – moist slopes and wooded or rocky hillsides, and dry to moist conifer and aspen forest openings. It is also found in grasslands and shrub associations, and occasionally in calcareous marshes.
Silver buffaloberry does well in dry sites but can adapt to soils that are often poorly drained and even slightly saline. In its native range, the species is typically found on river and creeks banks, low-lying somewhat marshy areas, wet meadows, floodplains, and the edge of springs and ponds. However it is intolerant of prolonged flooding and permanently high water-tables. It is usually in open or exposed areas, but will tolerate some shade.
Both Canada and silver buffaloberry have strong, deep root systems which – combined with their capacity for fixing nitrogen – allows them to grow in nutrient-poor soils.
Identifying buffaloberries
Shepherdia species grow as shrubs or small trees and are dioecious, with male and female flowers on separate plants. Leaves and branches are opposite, compared to the alternate pattern within the Elaeagnus genus. In both, stems, branches, leaves and some floral parts are densely covered in characteristic flat, scaly hairs that are either brown or grey.
Male shrub of Canada buffaloberry (Shepherdia canadensis) in full leaf in garden, Rio Terrace, Edmonton. 2023-06-29. Photo: P. Cotterill.
Female plant of Canada buffaloberry (Shepherdia canadensis) in fruit in home garden in Rio Terrace, Edmonton. 2023-06-12. Photo: P. Cotterill.
The flowers are small, almost inconspicuous, yellow-brown in colour and appear in tiny clusters which may be mistaken for catkins. Look for them before the leaves appear. Only the female plants produce the characteristic bright red, or less commonly yellow, berries. Look for thick, leathery foliage.
Male flowers are clustered in the leaf axils of the previous year's branches. The inflorescence displays as one to several small, inconspicuous, stalkless, axillary flowers. Petals are lacking, but there is an urn-shaped calyx of sepals with four triangular, petal-like lobes. Male flowers have eight extended stamens and the calyx lobes are strongly bent back (reflexed).
Female flowers, also in small clusters, are somewhat smaller and stiffer than the males, with a slender, capped style extending from the centre. In Canada buffaloberry, the inner surfaces of the calyx are smooth while outer surfaces are densely covered in rust-colored scales. The buffaloberries are among the earliest of shrubs to bloom in the spring; in the Edmonton area they flower in early May and are in fruit by June.
Clusters of male flowers and some unopened flower buds on branch of Canada buffaloberry (Shepherdia canadensis) in home garden, Rio Terrace, Edmonton. 2023-05-04. Photo: P. Cotterill.
Branch of female plant showing clusters of female flowers (note protruding stigmas and recurved sepal lobes), whitish scaly bark and brown "rusty" scales on the undersides of the leaves, which emerge in pairs from the bud erect like "praying hands." Canada buffaloberry (Shepherdia canadensis) transplanted into home garden, Rio Terrace, Edmonton. 2023-05-04. Photo: P. Cotterill.
Male flowers of silver buffalo berry (Shepherdia argentea). Note the twig tip ending in a thorn. Lethbridge, 2008-05-04. Photo: P. Cotterill.
Canada vs silver buffaloberry
Canada buffaloberry is typically shorter, up to 4 m high – no more than 2 m in cooler climates – with a loosely branched rounded outline. A clear distinction between the two species, apart from leaf colour and shape, is that silver buffaloberry has thorns, while Canada buffaloberry does not. Also, the new twigs on Canada buffaloberry are shiny and covered with rusty-brown scales that turn brownish-gray when they are eventually shed.
Canada buffaloberry leaves are elliptic to narrowly ovate, from 2 – 6.5 m long and 1-3 cm wide. The upper surface is dark green and smooth, sometimes with scattered star-shaped (stellate) hairs. The lower surface is greyish-green with dense stellate hairs and scattered, rust-coloured scales. Canada buffaloberry fruits are slightly hairy, with a fleshy consistency that feels "soapy" when crushed.
Silver buffaloberry plants are large shrubs to small trees, 4- 6 m high. Fruits are small, 7-10 mm across, flecked with red and often with silver. The leaves are narrower than those of Canada buffaloberry, 2 – 6 cm long, with a blunt tip and tapered at the base to a short stalk. The silvery upper surface has short, silvery scales, the lower surface paler and more densely scaly. New twigs are covered with silvery scales that shed the second season. A single thorn is often present at the tips of short branches.
For nitrogen fixing, choose buffaloberry
Shepherdias are non-legume nitrogen fixers, giving them great potential for improving poor soils and making nitrogen available for surrounding plants. The nitrogen-fixing bacteria associated with legumes is Rhizobia bacteria, while for buffaloberry it’s the Frankia genus.
A study at the University of Saskatchewan (3) shows that, while Shepherdia does not necessarily "fix" more nitrogen on a per-plant basis than an optimized legume, like alfalfa, its ability to thrive in harsh environments and add organic nitrogen to the soil through leaves and root turnover makes it a premier nitrogen-fixing plant, especially for restoration or permaculture applications in cold, harsh climates.
Wildlife and ecology
A single female buffaloberry plant can produce in excess of 10,000 fruits. Rich in Vitamin C, the berries support grouse and waxwings, as well as hares and other small mammals, and their flowers provide nectar for native bees in the spring (2). The shrub also provides important habitat for smaller fauna, as shelter and nesting sites.
While deer will occasionally browse on the twigs, bears and grouse eat large quantities of the berries. Studies have shown that Syrphidae flies are the main pollinator.
Buffaloberry for food and medicine
Though juicy, buffaloberry fruit, particularly of Canada buffaloberry, has a bland flavour and is sharply to somewhat bitter. Despite this, buffaloberry has been an important food and medicine plant for First Nations peoples of the central plains and Prairie Provinces. Pioneers also made extensive use of the plant, and the fruits still have many culinary uses today.
As well as being used in a host of therapeutic remedies by various Indigenous peoples, the berries were mixed with dried meat and fat in pemmican. The berries are also whipped up to make a relished dessert, although for European tastes it is best consumed with sugar! As well as their high content of vitamin C, the fruits are being investigated for antioxidant properties, and consideration has long been given to developing commercial crops from both species. (For much more information on these uses, as well as the ecology of the species, see E. Small and P. M. Catling’s paper in Poorly Known Economic Plants of Canada (1).)
In the garden
Both species’ resistance to exposure and spreading form are excellent for a low maintenance hedge – as an alternative to caragana, lilac or cotoneaster. They are also salt-tolerant, so can be used as a border or median for roads or pathways.
Silver buffaloberry suckers extensively compared to Canada buffaloberry which, however, can produce downward-curving branches that take root and can produce small thickets. The roots are prone to damage if they dry, so keep them moist after planting but, once established, buffaloberries are drought-tolerant, particularly those of silver buffaloberry.
Both species have relatively few insect or disease indications. Both grow in Zone 2, with Canada buffaloberry being the more cold-tolerant. Because they are dioecious, you need both male and female plants for pollination to produce berries.
Propagation
Growing buffaloberry from seed requires 60 – 90 days of cold-moist stratification. First macerate the berries in water, allow the seeds to settle and then decant and remove the chaff. This is repeated until only seeds remain; then spread them out to dry. Seeds can also benefit from light scarification, and need light to germinate. Whether the seedlings are male or female will not be known until they flower.
One of the simplest propagation methods is root cuttings or semi-hardwood cuttings, typically made in May when the leaf buds have just begun to break dormancy. They can also benefit from Frankia rhizobacteria inoculation as seedlings.
Layering, particularly for Canada buffaloberry, is a simple process of bending a low-hanging branch to the ground, covering a section with soil in spring and allowing it to take root before cutting it from the parent plant.
A native shrub with benefits
For an eye-catching focal point, or those looking for a low-maintenance landscape shrubin Edmonton, Canada buffaloberry offers year-round interest while supporting local wildlife. Plants bring both beauty and ecological benefits to your yard or garden.
One reviewer on the UBC Botanical Garden website perhaps says it best: “I've started a few Silver Buffaloberry plants in Northern BC. There is a plot there with terrible soil; hopefully, some nitrogen-fixers will help improve it. Also, I think Silver Buffaloberry . . . looks like small olive trees, which is about as close to olive trees as I'll get in a zone with such cold winters.”
(1) E. Small & P.M. Catling. Buffaloberry, Shepherdia canadensis (L.) Nutt. and S. argentea (Push) Nutt. in Poorly Known Economic Plants of Canada-32. February/fevrier 2002. CBA/ABC Bulletin 35 (1). https://www.cba-abc.ca/wp-content/uploads/2023/12/2002_35_1_Sheperdia-canadensis-and-S-argentea.pdf
(3) https://harvest.usask.ca/server/api/core/bitstreams/2124171d-fbc8-4048-856d-68c982e03513/content
Comparing Shepherdia canadensis to Shepherdia argentea
Canada buffaloberry and silver buffaloberry differ mainly in that S. argentea has thorns, silver-coloured leaves on both sides and sweeter fruit, while S. canadensis is thornless, has green leaves above, and bitter, soapy berries. S. canadensis is often found in forest understories northward to Yukon and Alaska, while S. argentea thrives in coulees and riparian areas, particularly in prairie regions.
Canada buffaloberry (Shepherdia canadensis) Light Requirement: sun, part shade, shade Soil Moisture: dry to moist Soil pH: alkaline Growth Rate: fast Lifespan: short Suckering: none, maintenance low Pollution tolerance: medium Drought Tolerance: medium Conditions Comments: Tolerates the poorest of soils due to nitrogen-fixing ability; does well in dry or alkaline situations. Extremely cold- and drought-tolerant. | Silver Buffalo Berry (Shepherdia argentea) Light Requirement: full sun Soil Moisture: dry to normal Soil pH: alkaline Growth Rate: medium Lifespan: medium Suckering: high, maintenance low Pollution tolerance: high Drought Tolerance: high Conditions Comments: This shrub is also known as one of the more salt-tolerant species for landscapes with saline soils. |
