Berberis koreana aka Barberry

Berberis koreana, or Korean barberry, belongs to the barberry family. It comes from Korea and grows as a woody shrub. Several stems form a dense, rounded or oval crown. Garden plants often reach 4–6 feet (1.2–1.8 metres) tall and wide. RHS gives a larger upper size of 8.2 feet (2.5 metres). Growth is moderate, and roots send up suckers. These shoots can form colonies around the parent plant. Leaves may fall or stay through part of winter.

The smooth stems have reddish-brown bark and many short spines. Some spines branch into several flattened points at each node. The leaves grow in an alternate pattern along the stems. Each simple leaf has an oval shape and rounded tip. Leaves measure 1–3 inches long and have toothed, spiny edges. Their summer colour ranges from medium to dark green. In autumn, they turn deep red or purple. Leaves can remain on the shrub late into the season.

Small yellow flowers hang in racemes during spring. Chicago Botanic Garden records bloom from May to June. The flowers draw pollinators and add colour before fruit forms. Small red berries ripen in autumn and may last through winter. They have an oval shape and a waxy surface. Flowers, fall leaves, and fruit provide interest across several seasons. Gardeners use the shrub in borders, groups, hedges, and screens. Its thorns also make it useful as a barrier.

Grow it in full sun or part shade. Full sun gives the best flower and fruit display. It accepts clay, loam, sand, and chalk with good drainage. Acid, neutral, and alkaline soils all suit it. It prefers moist soil but also tolerates drought. Sources place it in USDA zones 3–7 and UK rating H7. It needs little routine care and resists deer. Aphids, berberis sawfly, and powdery mildew can affect it. Its spines make handling hard and can trap fallen litter.

Sources disagree about whether its fruit and leaves are safe. PFAF lists raw or cooked fruit and cooked young leaves. RHS warns against eating the fruit, including feeding it to pets. NC State identifies bark, leaves, roots, and sap as poisonous. Eating these parts can cause nausea, vomiting, and diarrhoea. Keep the thorny shrub away from places where small children play. PFAF also records a yellow dye from its roots.