Ottawa barberry 'Superba'

Synonyms: Berberis х ottawensis 'Purpurea', Berberis thunbergii atropurpurea superba

Ottawa barberry Superba – a cultivar of Ottawa barberry. The cultivar received an award from the Royal Horticultural Society.

It is a tall deciduous shrub. Reaches 3-4 m in height and width. Grows quickly, reaching its final size at 8-10 years of age. Shoots initially grow upright, later arching and pendulous. Bark is reddish-brown. Thorns are three-parted, sharp, up to 2 cm long.

Leaves simple, alternately arranged, glossy, obovate or rounded, 3-5 cm long. Striking throughout the season – from dark red to purple with a bluish tinge. In autumn it acquires orange to light red shades. The only red-leaved barberry that retains its color even in shade.

Flowers in May. Flowers yellow-red, gathered in small raceme-like inflorescences of about 10 flowers, up to 5 cm long. Flowers emit a pleasant fragrance.

Fruits oblong, up to 0.8 cm long, light scarlet berries, glossy, edible, very sour, persist on the branches for a long time. Ripen in late September – early October.

Hardiness zone: 6 (-15 °C).

Location/exposure: sun-loving, but tolerates partial shade. Heat-resistant, winter-hardy, drought- and wind-resistant, relatively smoke-tolerant. Does not tolerate prolonged waterlogging. Prefers fertile, moderately moist soil. Tolerates urban conditions well.

Planting: planting is best carried out in spring or autumn. If soil acidity is above pH 7, it is recommended to lime the soil. Planting mix: peat, topsoil, humus, 400 g slaked lime (if pH>7) and 200 g wood ash. Planting hole dimensions: 40x40 cm. For single planting, distance between plants should be 1.5-2 m. To create a hedge, prepare a trench and place the shrubs at a rate of 2 plants per linear meter.

Care: care consists of loosening the soil around the trunk, but not deeply, and mulching. Watering is recommended at least once a week with 2-3 buckets per plant. In spring, one year after planting, nitrogen-containing fertilizers can be applied. Subsequently, nitrogen feeding is carried out no sooner than every 3-4 years. In the first 2-3 years it needs to be covered with conifer boughs for winter protection.

Pruning: tolerates trimming well.

Propagation: for spring sowing stratification is necessary at 1 - 5 °C for 3 - 4 months. Sowing depth of seeds 2 - 3 cm. Seed germination 5-12%, viability 60%. Rooting rate of summer cuttings 45%.

Diseases: bacterial canker, powdery mildew, leaf spot, rust fungus Puccinia graminis, powdery mildew.

Pests: barberry aphid, barberry sawfly, barberry fruit moth, leaf-eating insects.

Uses: used in single and group plantings, as a specimen on lawns, as well as in row plantings to create masses or edges, for creating freely growing hedges and borders, as a color accent in shrub and tree combinations, and also for creating mixed groups with perennials.