Berberis thunbergii
Japanese barberry
Japan; introduced to North America in the late 19th century and since naturalized widely across the northeastern and midwestern United States
Overview
Berberis thunbergii is a deciduous shrub in the family Berberidaceae native to Japan, reaching 3-6 feet (90-180 cm) tall and 4-7 feet (120-210 cm) wide in a dense rounded-to-broadly-arching mound with pendulous branch tips. Leaves are small, spatulate, 0.5-1.5 inches (1.2-4 cm) long, bright to medium green through spring and summer and turning vivid orange, red, and yellow in fall. Single sharp thorns occur at each node. From April through May, small pale yellow flowers 0.25-0.3 inch (6-8 mm) across hang in small clusters beneath the stems, partially concealed by foliage. Bright red oblong berries 0.3-0.4 inch (8-10 mm) long ripen in fall and persist through winter on bare stems, carrying winter color and providing bird food. The species is the parent of numerous landscape cultivars selected for purple, golden, or variegated foliage and for compact or upright habits — B. thunbergii 'Crimson Pygmy', B. thunbergii 'Rose Glow', B. thunbergii 'Concorde', B. thunbergii 'Rosy Rocket', and B. thunbergii 'Helmond Pillar' are representative cultivated forms. The species is classified as invasive in several northeastern and midwestern U.S. states — including Massachusetts, Connecticut, New York, Pennsylvania, and Ohio — where bird-dispersed seeds naturalize readily in disturbed forests and shrubby edges; planting is prohibited or regulated in those jurisdictions. The species is not currently regulated as invasive in Washington or Oregon. All parts of the plant are toxic to pets and humans if ingested because of berberine alkaloids concentrated in the bark, roots, and berries.
Native Range
Berberis thunbergii is native to Japan, where it grows on mountain slopes, forest margins, and rocky areas from near sea level to 5,000 feet (1,500 m) elevation. The species was introduced to North America in the late 19th century, originally as an ornamental shrub and as a replacement for Berberis vulgaris (common barberry) which had been banned as an alternate host for wheat stem rust, and has since naturalized widely across the northeastern and midwestern United States.Suggested Uses
Planted in mixed shrub borders, informal hedges, mass plantings, and erosion-control slopes where a tough adaptable thorny mounding shrub is wanted. Vivid fall color and persistent red berries carry late-season and winter interest. Deer-resistant foliage makes the species useful in pressured browse settings. Named cultivars selected for purple, golden, or variegated foliage or for compact or upright habits are generally substituted for the straight species in designed landscape applications. Not suited to positions adjacent to natural areas where bird-dispersed seedling escape is documented, jurisdictions where the species is prohibited as invasive, high-traffic pedestrian pathways where the sharp thorns conflict with regular contact, or landscapes with pets or young children where the toxic berries pose an ingestion risk.How to Identify
Appearance
Size & Dimensions
Height3' - 6'
Width/Spread4' - 7'
Reaches mature size in approximately 6 years
Bloom Information
Small pale yellow flowers 0.25-0.3 inch (6-8 mm) across open in small clusters beneath the stems from April through May, partially concealed by foliage and averaging 2-3 weeks of bloom. The flower display is not an ornamental feature. Red oblong berries 0.3-0.4 inch (8-10 mm) long ripen from September through October and persist through winter on bare stems after leaf drop.
Detailed Descriptions
Flower Description
pale yellow; small, 0.25-0.3 inch (6-8 mm) across; borne in small clusters beneath the stems and partially hidden by foliageFoliage Description
bright to medium green in spring and summer; vivid orange, red, and yellow in fall; spatulate leaves 0.5-1.5 inches (1.2-4 cm) longGrowing Conditions
Sun Requirements
Requires 4-8 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
Care & Maintenance
Care Guide
Plant in well-drained soil with a pH of 5.5-7.5 in full sun to part shade; tolerated soil types include loam, clay, sand, and silt. Full sun produces the most vivid fall color, and part shade is tolerated but reduces fall color intensity. Water weekly through the first 1-2 growing seasons; established plants are very drought-tolerant and tolerate compacted urban soils, road salt, and air pollution. Positions adjacent to forest edges, stream corridors, or natural areas are not suited to the species because bird-dispersed seeds escape from ornamental plantings and naturalize in nearby habitats. The species is classified as invasive and banned in several northeastern and midwestern U.S. states; local invasive-species regulations govern whether the species is legal to plant outside Washington and Oregon. All parts of the plant are toxic to pets and humans if ingested because of berberine alkaloids concentrated in the bark, roots, and berries. Stems carry sharp single thorns at each node that cause minor puncture wounds during handling.Pruning
Pruning is done after flowering (May through June) or during dormancy (November through December). Dead, damaged, or crossing branches are removed at the branch collar. Shearing maintains size and shape for hedge and formal border use. Hard renovation pruning to within 6-12 inches (15-30 cm) of the ground in late winter resets an overgrown specimen — the species regenerates vigorously from the base. Sharp single thorns at each node cause frequent puncture wounds during handling of pruning debris and removed stems.Pruning Schedule
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late springwinter