Korean fir 'Silberlocke'

Synonyms: Korean fir 'Silberlocke', Abies koreana 'Horstmann's Silberlocke'

Korean fir 'Silberlocke' – a very striking cultivar of Korean fir. The cultivar was developed in Germany by gardener Günther Horstmann (Gunter Horstmann) in 1986. The form was awarded the Royal Horticultural Society's AGM (Award of Garden Merit).

It is a small tree with a regular conical or pyramidal symmetrical crown, sometimes with 2-3 tops. It reaches 5 m in height with a crown diameter of 3 m. The plant is slow-growing, the annual increase reaching 6-8 (10) cm. At 10 years it grows to 1.2-2 m with a crown diameter of 1.5 m. The trunk is straight and even. Scaffold branches are straight and even, spreading evenly to the sides, heavily branched, arising from the trunk at an acute angle and directed sideways and upwards. The bark of young trees is light grey, smooth, later becoming fissured with reddish-brown cracks. Young shoots are covered with fine hairs, yellowish, later purple.

The foliage is very ornamental, dark green above and silvery-white below. The needles are curved so that their pale underside is visible. Because of this, the foliage appears to be covered with frost.

Cones are purple-violet, cylindrical, 5-7 cm long and 2-2.8 cm wide. It fruits abundantly at a young age. They appear in spring.

Hardiness zone: 5-7

Location: Prefers sunny sites but can tolerate partial shade. Tolerance to urban conditions is medium. Prefers fresh fertile soil with even moisture. Prefers sandy loam or loamy soil. Needs protection from cold winter winds. Does not tolerate drought. A compact dense crown develops in open sunny positions.

Planting: for avenue plantings the recommended distance between trees is at least 4-5 m, in dense groups 2.5 m, in loose groups 3-3.5 m. Optimal planting times: spring in April, autumn – late August through September. Minimum planting hole dimensions: 50x50x60 cm. The root collar should be at ground level. Recommended soil mix: peat, sand, clay, leaf mold or humus in the ratio 1:1:2:3. On heavy soils drainage is mandatory – place broken brick or crushed stone at the bottom of the hole in a 20 cm layer. When planting it is recommended to add nitroammophoska in the amount of 250-300 g per hole and 10 kg of sawdust. The optimal planting age is 5-10 years.

Care: In the 2nd-3rd year after planting it is recommended to apply Kemira-Universal (150 g/m²). Loosen the soil to a depth of 25-30 cm. Mulch the trunk circle with sawdust, peat or wood chips in a layer of 5-8 cm. Young plants need to be sheltered with conifer boughs in severe winters.

Pruning: sanitary pruning is carried out in early spring.

Diseases and pests: Resistance to pests and diseases is high. Preventive treatment against adelgids is recommended.

Propagation: Propagated by seed, cuttings and grafting. When grown from seed there is a fairly high percentage of inheritance of ornamental traits.

Usage: Used in Japanese gardens and rock or alpine gardens, to create a focal point in the foreground of landscape groups. Looks good in solitary plantings.