What hardiness zones is Mahonia repens suitable for?

A low-growing, creeping broadleaf evergreen shrub reaching 6-12 inches (15-30 cm) tall and 2-4 feet (0.6-1.2 m) wide. Growth rate is slow, adding 2-4 inches (5-10 cm) per year. Spreads by underground rhizomes to form a dense, mat-like groundcover over time. Leaves are pinnately compound, 6-10 inches (15-25 cm) long, with 3-7 (typically 5) broadly ovate, holly-like leaflets, each 1-2.5 inches (2.5-6 cm) long with wavy, spiny margins. Leaflets are notably rounder, fewer, and more widely spaced than those of M. aquifolium or M. nervosa. New growth emerges bronze to reddish-bronze, maturing to a dull blue-green to medium green surface that is less glossy than M. aquifolium. In winter, foliage develops purple to reddish-purple tones. Flowers appear in April to May in short, compact terminal racemes 1-3 inches (2.5-8 cm) long, bright yellow, each approximately 0.3 inches (8 mm) across. Fruit is a cluster of globose berries approximately 0.3 inches (8 mm) in diameter, ripening to dusty blue-black with a glaucous bloom by July to August. Berries are tart and edible. Inner bark is yellow from berberine alkaloid. The most cold-hardy of the western native mahonias, tolerating temperatures to approximately -30°F (-34°C). Tolerates drier and sunnier conditions than M. nervosa. Less susceptible to powdery mildew and rust than M. aquifolium.

Native Range

Native to western North America with a broad range from British Columbia east to the Black Hills of South Dakota and south through the Rocky Mountain states to New Mexico and Arizona. Found in open pine forests, dry montane woodlands, rocky slopes, and forest clearings from approximately 2,000 to 10,000 feet (600-3,000 m) elevation. The broadest geographic range and highest elevation tolerance of any North American Mahonia species.

Suggested Uses

Commonly used as a native groundcover in dry shade, rock gardens, and naturalized areas at 2-3 foot (0.6-0.9 m) spacing. The low mat-forming habit makes it suitable for underplanting beneath native conifers and oaks. Tolerates drier and more sun-exposed conditions than other Pacific Northwest mahonias. Suitable for slope stabilization on dry, rocky banks. Berries provide food for birds. The cold hardiness (zone 4) extends its usefulness further inland than M. nervosa or M. aquifolium.

How to Identify

Distinguished from other native mahonias by its low, creeping, mat-forming habit (6-12 inches / 15-30 cm) and compound leaves with only 3-7 broadly ovate, rounded leaflets per leaf. Leaflets are notably wider, rounder, and fewer than those of M. nervosa (9-19 narrower leaflets) or M. aquifolium (5-9 leaflets, taller plant). Leaf surface is dull blue-green to medium green, less glossy than M. aquifolium. The rhizomatous, carpet-forming growth pattern is the most distinctive feature, creating dense mats closer to the ground than any other western Mahonia.

Appearance

Size & Dimensions

Height6" - 1'

Width/Spread2' - 4'

Reaches mature size in approximately 5 years

Colors

Flower Colors

Foliage Colors

Bloom Information

Bloom Period

~3 weeks

Spring

Flowers from April to May in USDA zones 4-8. Short, compact terminal racemes 1-3 inches (2.5-8 cm) long bear bright yellow flowers, each approximately 0.3 inches (8 mm) across. Bloom lasts 2-3 weeks. Dusty blue-black berries with a glaucous bloom ripen in July to August. Flowers provide early-season nectar for native bees and other pollinators.

Detailed Descriptions

Foliage Description

Bronze new growth; dull blue-green to medium green in summer; purple to reddish-purple in winter

Growing Conditions

Sun Requirements

Full Sun Partial Shade

Requires 3-8 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.0 - 7.5(Neutral)

357912

Soil Types

loam sand rocky

Drainagewell drained

Water & Climate

Water Needs

Very Low

Frost Tolerance

hardy

Time to Maturity

3-5 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant in partial shade to full sun in well-drained soil. More sun-tolerant and drought-tolerant than either M. nervosa or M. aquifolium, reflecting its native habitat in dry, open montane forests. Adapts to a range of soil types and pH levels (5.0-7.5), including rocky and gravelly soils. Water occasionally during extended dry periods in the first two years; established plants tolerate prolonged summer drought without supplemental irrigation. Mulch lightly with 1-2 inches (2.5-5 cm) of organic material or gravel. Generally free of the rust and mildew problems that afflict M. aquifolium. Slugs may damage new growth in wet spring conditions. The slow spreading rate means patience is required for groundcover coverage.

Pruning

Minimal pruning needed. Remove any winter-damaged or discolored leaves in early spring before new growth begins. The naturally low, spreading habit requires no shaping. If the planting becomes too dense or extends beyond desired bounds, dig out sections at the perimeter in spring, severing rhizome connections with a sharp spade.

Pruning Schedule

early spring

Maintenance Level

very low

Container Growing

✓ Suitable for container growing

Minimum container size: 3 gallons

⚠️ Toxicity Warning

Non-toxic