Oregon Grapeholly or Oregon Hollygrape

(Berberidaceae - Barberry Family)

Form

• small broadleaf evergreen ornamental shrub
• maturing at about 5' tall by 3' wide
• upright oval to semi-procumbent growth habit
• slow growth rate

Culture

• partial sun to full shade
• does best in partial shade in moist, rich, well-drained, acidic soils; not especially tolerant of alkaline pH soils, poor soils, compacted soils, clay soils, wet soils, heat, full sun, exposed sites, or at windswept corners of foundations
• propagated by seeds, stem cuttings, or division of multi-stemmed parent plants
• Barberry Family, with several minor disease and pest problems, but most often troubled by improper placement in the landscape (see above), resulting in stunting, foliage chlorosis, and/or foliage Winterburn
• moderately available, in ball and burlap or container form
• needs a protected site in Winter against prevailing winds, channeling winds, and direct sunshine (as do all broad-leaved evergreens to avoid Winter foliage dessication)

Foliage

• emerging reddish, changing to light bronzed-green, turning lustrous dark green,then finally becoming a deep burgandy in Winter, but often subject to "burning" in Winter, resulting in a bleached appearance of the foliage
• evergreen, alternate, odd-pinnately compound, with 5 to 9 leaflets that are individually elliptical to ovate, very spiny-dentate on the margins, and glossy

Flowers

• bright yellow, flowering in April, with a dense cluster of many small flowers in a large terminal and smaller lateral inflorescences, attracting many bees and slightly fragrant
• the inflorescences are an attractive contrast against the previous year's burgandy foliage and the newly emerging red foliage

Fruits

• clusters of ellipsoid green berries mature to a blue-black color with a white cast (a "bloom" on the cuticle, as in Blueberries or Grapes) in August and September, and may persist into December
• immature fruits often prematurely abscise and are not present at all

Twigs

• light brown, fairly stout, virtually unbranched, and with a coarse texture (numerous leaf and bud scale scars are present from previous years along the stems due to their slow growth rate)
• several stems emerge from the base of each shrub
• Winter buds are small, except for the large terminal floral buds

Trunk

• not applicable

ID Summary

• pinnately compound, alternate, leathery, spiny leaves are glossy, evergreen, and heavily bronzed in Winter
• leaves, flowers, and fruits occur at the top of the slow-growing, relatively unbranched stems, with several upright or procumbent stems for each shrub
• bright yellow flowers in early Spring top the stems, attract many bees, and may give rise to blue fruits in late Summer

USAGE

Function

• foundation, entranceway, group planting, or specimen broadleaf evergreen shrub

Texture

• bold texture
• open density

Assets

• bold texture (resulting from the large spiny foliage and coarsely branched stems)
• ever-changing color of bronzed, green, or burgandy evergreen foliage
• bright yellow flowers in Spring
• occasional terminal clusters of blue berries in late Summer and Autumn

Liabilities

• significant Winterburning of the burgandy evergreen foliage
• slow growth rate and establishment
• chlorotic foliage in akaline soils
• flowers attract numerous bees (this can be an asset if pollination of nearby plants is desired)
• stems are sometimes sprawling, giving an unkempt, ragged appearance

Habitat

• zones 5 to 8
• native to the Pacific Northwest of the United States

SELECTIONS

Alternates

• small to medium-sized shrubs of broadleaved evergreen habit (Buxus hybrids, Ilex x meserveae, Ligustrum japonicum, Rhododendron hybrids, etc.)
• small to medium-sized plants of bold character for shady sites(Acanthus species, Hosta cultivars, Hydrangea species, Rhododendron catawbiense, etc.)
• shrubs that have deeply bronzed evergreen foliage in Winter (Cotoneaster salicifolius, Nandina domestica 'Firepower', etc.) or groundcovers with the same trait (Euonymus fortunei 'Colorata', Sedum kamtschaticum floriferum 'Weihenstephaner Gold', etc.)

Variants

• Mahonia aquifolium 'Compactum' - compact and slower-growing form to 3' tall
• Mahonia repens - Creeping Mahonia - a species similar to Oregon Grapeholly in its foliage, flowers, fruit, and hardiness, but differing in its short height (to 1' tall), stoloniferous habit (creating numerous basal stems over time), and trailing appearance, used as a non-traditonal, bold-textured groundcover

NOTES

Translation

• Mahonia is named after Bernard McMahon, an American horticulturist of the 18th-19th century.
• aquifolium translates as "eagle foliage", referring to the bold, spreading, pinnately compound leaves.

Purpose

• Oregon Grapeholly is one of the best broadleaf evergreen small shrubs with brilliant Winter bronzing of its bold-textured foliage (when placed in wind- and sun-protected sites).

Summary

• Mahonia aquifolium is a small, evergreen, bold-textured shrub, known for its deep burgandy Winter foliage, emerging reddish Spring foliage, yellow early Spring flowers, and occasional late Summer and Autumn blue fruits.