1 / 5
Berberis thunbergii f. atropurpurea
purpleleaf or redleaf Japanese barberry
Parent species {Berberis thunbergii} native to Japan; forma atropurpurea arose in cultivation as a seed-grown purple-leaved selection
Learn more
Overview
Berberis thunbergii f. atropurpurea is a mounding deciduous shrub form in the family Berberidaceae, reaching 3-6 feet (90-180 cm) tall and 4-7 feet (120-210 cm) wide. The forma is a seed-grown purple-leaved variant of the species — seedling variation in color intensity is the rule, and individual plants range from deep burgundy-red to bronze-burgundy. Leaves are small, spatulate, 0.5-1 inch (1.3-2.5 cm) long, deep purple-red in full sun and fading toward burgundy-green in shade. Single sharp thorns occur at each leaf node. Small yellow bell-shaped flowers 0.25 inch (6 mm) across hang beneath the stems from April through May, largely concealed by foliage. Small red oblong berries 0.3 inch (8 mm) long ripen in fall and persist through winter on bare stems. Fall foliage turns orange-red. Growth is slow to moderate. The forma is the parent of numerous named clonal cultivars selected for more uniform color or compact size, including B. thunbergii 'Rose Glow', B. thunbergii 'Royal Burgundy', and B. thunbergii 'Crimson Pygmy'. The parent species B. thunbergii is classified as invasive in several northeastern and midwestern U.S. states where planting is prohibited or regulated. Research from the Connecticut Agricultural Experiment Station has documented elevated populations of the black-legged tick (Ixodes scapularis) — the primary vector of Lyme disease in the eastern United States — in barberry-infested forest understory compared to barberry-free reference sites, with the dense thorny canopy holding higher humidity at ground level and harboring more white-footed mice that serve as tick reservoirs. 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. Forma atropurpurea arose in cultivation as a seed-grown purple-leaved variant of the species and does not occur in wild populations. Birds consume the persistent red berries of all B. thunbergii forms and disperse seeds into surrounding habitats, which has driven the invasive status of the species across the eastern United States.Suggested Uses
Planted as a hedge, barrier planting (the dense thorns deter foot traffic and most browsing animals), mass planting, or specimen at 4-7 foot (120-210 cm) spacing depending on the cultivar form. Grown in containers of 5 gallons (19 L) or more with a well-drained mix. Combined with chartreuse-foliaged Spiraea cultivars, silver-foliaged Stachys byzantina, or golden-foliaged Physocarpus opulifolius 'Dart's Gold' for color contrast in mixed borders in zones 4-8. Named clonal cultivars are typically substituted for the seed-grown forma in designed landscape applications where color uniformity is wanted. Not suited to positions adjacent to natural areas where bird-dispersed seedling escape is a concern, jurisdictions where B. thunbergii is prohibited as invasive, properties in Lyme-endemic regions where the documented tick association is a concern, 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 5 years
Bloom Information
Small yellow bell-shaped flowers 0.25 inch (6 mm) across hang in small clusters beneath the stems from April through May, averaging 2 weeks of bloom. Flowers are largely concealed by foliage and are not an ornamental display. Red oblong berries 0.3 inch (8 mm) long ripen from September through October and persist on bare stems through winter after leaf drop.Detailed Descriptions
Flower Description
yellow; small, 0.25 inch (6 mm) across, bell-shaped; hanging beneath the stems and largely concealed by foliageFoliage Description
deep purple-red in full sun, fading to burgundy-green in shade; small spatulate leaves 0.5-1 inch (1.3-2.5 cm) long; orange-red in fallGrowing 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 6.0-7.5 in full sun where the purple-red foliage color holds darkest. Tolerated soil types include loam, sand, and clay. Water weekly through the first 1-2 growing seasons; established plants are very drought-tolerant. The species is classified as invasive in several northeastern and midwestern U.S. states and planting is regulated or prohibited in those jurisdictions; local invasive-species regulations govern whether the forma is legal to plant in a given area. Research from the Connecticut Agricultural Experiment Station documents elevated black-legged tick populations in barberry-infested forest understory in the eastern U.S., and gardeners in Lyme disease endemic regions can factor that association into siting decisions. All parts of the plant are toxic to pets and humans if ingested. Sharp thorns at each node cause puncture wounds during handling of stems and pruning debris.Pruning
Pruning is done in early spring (March through April) before new growth emerges, or after flowering in May and June. Dead, damaged, or crossing stems are removed at the branch collar. Light shearing maintains size and shape for hedge and formal border use. Hard renovation pruning to within 6 inches (15 cm) of the ground in late winter resets an overgrown specimen because the forma regenerates vigorously from the base. Sharp single thorns at each node cause frequent puncture wounds during handling of pruning debris, and stout pruning gloves and long sleeves are the standard work-clothing for the task.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
early spring
Maintenance Level
lowContainer Growing
✓ Suitable for container growing
Minimum container size: 5 gallons