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 three to seven 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

Family: Berberidaceae

Plant type: shrub

USDA hardiness zones: 5B through 8 (Figure 1)

Planting month for zone 7: year round

Planting month for zone 8: year round

Origin: not native to North America

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 plant

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 .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

Invasive potential: not known to be invasive

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.