Culture
Easily grown in average, dry to medium, well-drained soil in full sun. Tolerates part shade, but performs best with full sun. This is a very adaptable shrub that is tolerant of urban conditions. Plants also tolerates heat and drought, but are generally intolerant of poorly-drained, wet soils. Plants spread slowly by creeping roots. Plants can also spread by self-seeding (birds will eat the fruits and distribute the seed). Plant branches may root where they touch the ground. This species is considered to be highly invasive in some areas (particularly in eastern North America).
Noteworthy Characteristics
Berberis thunbergii, commonly called Japanese barberry, is a spiny, broad-rounded, deciduous shrub with obovate green leaves. It typically matures to 5' tall and as wide. Leaves (variably sized to 1 1/4” long) typically turn attractive shades of orange, yellow and red in fall.
Genus name comes from the Latinized form of the Arabian name for the fruit.
Specific epithet honors Swedish botanist Carl Peter Thunberg (1743-1828) who reportedly identified this species in Japan in 1784.
'Pygruzam' PYGMY RUBY is a red-leaved, dwarf selection of Japanese barberry which will grow slowly to reach up to 1.5' tall with a 3' spread. It has a dense, rounded growth habit with small thorns along its branches. The inconspicuous flowers will ripen to small, red berries which are eaten by birds.
Problems
No serious pest problems. Some susceptibility to bacterial leaf spot, anthracnose, root rots, wilt, aphids, barberry webworm and scale. Spiny stems often trap unsightly wind-blown trash. Deer resistant. This species is known to be highly invasive in portions of the eastern United States, spreading readily by bird-dispersed seeds and forming impenetrable thickets which leaf out before native understory species, shading out wildflowers and other native plants.
Uses
Accent for small areas in the landscape. Foundations. Shrub border. Hedge or edger. Spiny barrier plant.