Introduction
With holly-like leaves, blue fruits, and striking yellow flowers, Oregon holly has much to offer in the landscape. Plants will grow in sun or shade but should be shaded in the winter to prevent the purplish leaves from browning. Transplanting is most successful with either potted or balled and burlapped plants. Oregon holly reaches 3 to 7 feet tall with an equal spread. Plants grow moderately fast, spreading by the suckering root system.
General Information
Scientific name: Mahonia aquifolium
Pronunciation: mah-HOE-nee-uh awk-kwiff-FOLE-lee-um
Common name(s): Oregon grapeholly, Oregon hollygrape, hollyleaved barberry
Family: Berberidaceae
Plant type: shrub
USDA hardiness zones: 5B through 8 (Figure 5)
Planting month for zone 7: year round
Planting month for zone 8: year round
Origin: not native to North America
Invasive potential: not known to be invasive
Uses: border; mass planting; container or above-ground planter; specimen; accent
Availability: somewhat available, may have to go out of the region to find the plan
Description
Height: 3 to 6 feet
Spread: 3 to 4 feet
Plant habit: upright
Plant density: open
Growth rate: slow
Texture: coarse
Foliage
Leaf arrangement: alternate
Leaf type: odd-pinnately compound
Leaf margin: spiny
Leaf shape: ovate
Leaf venation: pinnate; palmate
Leaf type and persistence: evergreen
Leaf blade length: 2 to 4 inches
Leaf color: green
Fall color: no fall color change
Fall characteristic: not showy
Flower
Flower color: yellow
Flower characteristic: winter flowering; spring flowering; pleasant fragrance
Fruit
Fruit shape: oval
Fruit length: less than 0.5 inch
Fruit cover: fleshy
Fruit color: black
Fruit characteristic: attracts birds
Trunk and Branches
Trunk/bark/branches: not particularly showy; typically multi-trunked or clumping stems
Current year stem/twig color: brown
Current year stem/twig thickness: thick
Culture
Light requirement: plant grows in part shade/part sun; plant grows in the shade
Soil tolerances: slightly alkaline; clay; sand; acidic; loam
Drought tolerance: moderate
Soil salt tolerances: unknown
Plant spacing: 24 to 36 inches
Other
Roots: usually not a problem
Winter interest: no special winter interest
Outstanding plant: plant has outstanding ornamental features and could be planted more
Pest resistance: no serious pests are normally seen on the plant
Use and Management
Cultivars include ‘Compacta’—about three feet tall; ‘King’s Ransom’—upright with bluish green leaves that turn bronze-red in winter, somewhat more tolerant of winter weather; ‘Mayhan Strain’—dwarf with glossy leaves; ‘Repens’—can be used as a ground cover.
Pests and Diseases
Several leaf spots may be seen, but infected leaves can be picked off and destroyed.