Native Plant Propagation Guidelines:
shrubs

Mahonia aquifolium (tall Oregon-grape)

Category: 
shrubs

tall Oregon-grape (Photo by Dave Polster)

Evergreen shrub from a rhizome; stems branched, stoloniferous to stiffly erect, 0.5-2.5 meters tall; bark and wood yellowish. Leaves: Evergreen, holly-like, alternate, pinnate; leaflets usually five to eleven, pinnately nerved more than twice as long as broad, mostly with 12-29 prominent spiny teeth, shiny above but less so beneath. Flowers: Inflorescence of clustered racemes 3-8 cm long; flowers yellow, the segments in sixes. Fruits: Clustered berries 7-14 mm in diameter, blue, glaucous, with a few large seeds, edible (Douglas et al., 1998).

Scientific Name: 

Mahonia aquifolium (Pursh) Nutt. (Berberis aquifolium Pursh)

Family: 
Berberidaceae
English Name: 
tall Oregon-grape
Other Names: 
barberry, tall mahonia, shining Oregon-grape

Geographical Range and Habitat Requirements

Ecological Setting: 

Mesic to dry open or closed forests in the lowland steep and montane zones (Douglas et al., 1998), open sites (Pojar et al., 1994) and woods and thickets (Peck, 1961). Occurs from southern BC south through Washington, Oregon to California. Found from sea level to 1800 m in BC (Pojar and MacKinnon, 1994).

Soil Texture: 

Rocky sites with coarse and medium textured, well-drained soils (Pojar and MacKinnon, 1994).

Nutrients: 

Nitrogen-medium soils (Klinka et al., 1989).

Soil Reaction and Salinity: 

pH 5 to 8 (USDA NRCS, 2001).

Moisture Regime: 

Moderately drought tolerant (Keator, 1994). Dry to moderately-dry; characteristic of moisture deficient sites (Klinka et al., 1989).

Shade Tolerance: 

Shade tolerant but prefers open exposed sites (Klinka et al., 1989).

Successional Status: 

Early successional to climax. Common on disturbed sites and under open-canopy Douglas-fir forests in the coast and interior (Klinka et al., 1989).

BEC Zone and GOE Community Status: 

CDF, IDF, ICH dry, PP, BG

Uses

Site Rehabilitation: 

Good species for stabilization of dry exposed sites because of its rhizomatous growth habit.

Wildlife: 

Occasional winter browse of deer and elk (USDA, 1988). Leaves and fruit eaten by small birds and mammals.

Landscaping: 

High quality landscaping plant. Useful in shrub borders, mixing well with other evergreen species. Showy, fragrant yellow flowers; edible berries; evergreen with some colour change in winter (S. Bastin, personal communication).

First Nations: 

Eaten mixed with salal or other sweet fruit. Shredded bark or roots used to dye basket materials bright-yellow. Bark and berries used medicinally for liver, gall-bladder and eye problems. (Pojar and MacKinnon, 1994).

Other Uses: 

Used in floral arrangements. Used to make jellies, preserves and wine.

Seed Propagation

Flowering Time: 

April - early May

Fruit Ripening Time: 

Mid-July – August

Seed Collection Time: 

August - September

Crop Intervals: 

Annual

Number of Seeds per Kilogram: 

83,000 -94,000

Seed Viability: 

Germination variable - 30-50% (Marchant and Sherlock 1984).

Fruit and Seed Collection and Extraction: 

Hand picking or flail onto cloths. Macerate berries immediately in water using a blender, and screen out or float off the pulp. Check fruits frequently prior to collection to determine collection timing and to avoid losses to birds and mammals. Mature seeds are a dark burgundy in colour and 3-5 mm in length.

Seed Storage: 

Dry seed superficially and store in sealed containers at 2-5º C (Rudolf, 1974; Banerjee et al., 2001).

Fruit/Seed Dormancy and Treatment: 

Stored seeds cold stratified for 90 days before planting in the spring. Alternatively for best results, sow seeds in fall covered with 0.3-1.3 cm of soil plus 0.5 cm of sand, and mulch until germination begins (Rose et al., 1998).

Vegetative Propagation

Method Success Rate Time of Collection
Softwood cuttings Good Late spring to early summer
Semi-hardwood cuttings Moderate to good Late summer to early fall from shoots of current year's growth
Hardwood cuttings Moderate to good Late fall through early winter from current years wood that is dormant, leafless and buds not yet swollen
Root cuttings High Spring
Suckers Good Spring
Plant division n/a n/a

Treat cuttings with rooting hormone and use 2:1 vermiculite:sand medium in a cold frame (Rose et al., 1998).

Outplanting Characteristics and Requirements

Outplant seedlings after two years (Rudolf, 1974). Can take full sun but is more attractive in partial shade in hot areas. Needs shelter from the wind in cold areas or leaves will burn. Prune old or too-tall stems at ground level in early spring. New growth will replace pruning. (Tenenbaum, 1994).

Additional Information and Photos

For more information and pictures, visit the E-Flora BC website at www.eflora.bc.ca.

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