Thunberg's Barberry 'Ruby Star'

Thunberg's Barberry Ruby Star (Berberis thunbergii Ruby Star) – a cultivar of deciduous shrubs from the species Barberry of the genus Berberis (Berberis) in the family Berberidaceae. The cultivar was developed by Polish selection, obtained at the Ergon Kwekerij nursery in 2015 for Plantarium. It was awarded a bronze medal at the international Plantarium exhibition.

A deciduous shrub up to 40 cm in diameter and up to 30 cm in height. Crown compact, rounded. Shoots red-orange or bright red, later becoming brown or dark brown, covered with spines up to 1 cm long, rigid, simple.

Leaves graceful, small, 1-3 cm long and up to 1 cm wide, rhombic-ovate, spatulate or rounded, with a pointed or rounded apex, narrowed at the base and passing into a short petiole, entire-margined, carmine-red in color, retaining color until late autumn.

Flowers gathered in few-flowered short racemes of 2-5 in clusters or singly, yellow, reddish on the outside, up to 1 cm in diameter, with a sweet-tart aroma. Blooms in May for 8-12 days.

Fruits small, bright red berries, ellipsoid in shape, shiny, up to 1 cm long, have a bitter taste and therefore are not suitable for eating. Fruits annually, fairly abundantly. Fruits ripen in September-October and remain on the branches for a long time.

Hardiness zone: zone 3 (-34°C).

Location: winter-hardy, drought-tolerant. Not demanding to soil, can grow on poor soils. Grows well on dry and sandy soils. Prefers soil with neutral acidity but can also grow on higher acidity. Does not tolerate waterlogging. Light-loving. Tolerates urban conditions well.

Planting: planting is best carried out in spring or autumn. If acidity is above pH 7, liming the soil is recommended. Planting mix: peat, turf soil, humus, 400 g slaked lime (if pH>7) and 200 g wood ash. Planting hole size: 40x40 cm. For single planting, the distance between plants should be 1.5-2 m. To create a hedge, prepare a trench and place bushes at a rate of 2 bushes per 1 linear meter.

Care: care consists of loosening the root circles, 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. Further nitrogen feeding should not be carried out earlier than after 3-4 years.

Pruning: tolerates cutting well.

Propagation: for spring sowing of seeds stratification is necessary at 1 - 5°C for 3-4 months. Seeds can also be sown in autumn without stratification immediately after harvest or cleaned of pulp. Sowing depth 2-3 cm. Rooting rate of summer cuttings 80-90%. Seed viability 92%.

Diseases: bacterial canker, powdery mildew, septoria leaf spot, infectious branch dieback, phyllosticta leaf spot, leaf spot. Not affected by rust.

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

Usage: ideal for small gardens, rock gardens (alpines), container landscaping