Berberis thunbergii 'Admiration'

Synonyms: Thunberg's barberry 'Admiration', Berberis thunbergii 'Orange Compact'

Thunberg's barberry 'Admiration' – a promising shrub cultivar of the species Berberis thunbergii. Awarded the RHS AGM (Award of Garden Merit) in 2009. Raised at a nursery in Boskoop (Netherlands).

It is a small shrub with a rounded, very dense but uneven crown. Reaches 0.3-0.4 m in height and width (0.5 m in favorable conditions). Grows slowly, annual increase 3-4 cm in height and 6-8 cm in width. Shoots brown, short, angled, covered with small spines.

Root system superficial, well-branched, with a large number of fine roots.

Leaves rounded or ovate, alternately arranged, up to 3.5 cm long, deep red or dark orange, with a striking yellow margin.

Flowers in May. Flowers small, up to 1 cm in diameter, yellow-red, solitary or in clusters of 2-5, few in number.

Fruits elongated raspberry-red berries, inedible. Ripen in October.

Hardiness zone: 7a (-15°C). In severe winters the non-woody parts of shoots may be damaged by frost. Young plants are recommended to be protected for the winter.

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

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

Care: care consists of shallow loosening of the root circles 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 may be applied. Further nitrogen feeding should be done no earlier than every 3-4 years.

Pruning: tolerates trimming well.

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

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

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

Uses: Good nectar source. In landscape design used for creating low borders, in rock gardens and alpine beds, in compositions, in single and group plantings.