Schrenk's spruce

Synonyms: Abies schrenkiana (Fisch. & C.A.Mey.) Lindl. & Gordon, Picea orientalis var. longifolia Ledeb., Pinus orientalis var. longifolia (Ledeb.) Ledeb., Picea obovata var. schrenkiana (Fisch. & C.A.Mey.) Carrière, Picea robertii Vipper, Pinus schrenkiana (Fisch. & C.A.Mey.) Antoine

Schrenk's spruce – a species of evergreen trees of the genus spruce in the family Pinaceae. Naturally occurs in the Tien Shan, Dzungarian Alatau, and in western and southern China. It ascends the mountains to elevations of 1300-2700 m above sea level. Forms pure and mixed forests on rocky sites. In cultivation since 1880. Known in Europe since 1877.

First described by Meyer and Fischer from herbarium specimens collected in the Dzungarian Alatau by the traveler Schrenk. Externally similar to Siberian spruce, from which it differs by longer needles, glabrous young shoots, and larger cones.

It is a tall tree reaching 20-30 (40-60) m in height with a trunk diameter up to 2 m. In youth it is slow-growing, annual increment 5-7 cm. Crown narrow-pyramidal or columnar, sparsely branched low, with drooping branches on mature trees. Bark reddish-dark-brown, later becoming gray. Young shoots yellow-gray, glabrous, slightly resinous. Buds globose-conical, 4-5 mm long and 2-3 mm wide, light reddish-brown. Bud scales not elongated, obtuse.

Root system superficial, well developed. The feeding area of a single tree can reach hundreds of square meters.

Needles four-sided, light green or pale blue, stiff, sharp, with a rounded or gradually pointed tip, arranged radially, straight or slightly curved, directed forward, 20-35 mm long and 1-1.5 mm wide. Stomatal lines well visible, arranged 2-3 on the upper side, 3-4 on the lower side. Needles sit almost at a right angle and around the entire shoot.

Cones oblong-cylindrical, 7-15 cm long and 2.5-3.5 cm wide, unripe – green, when ripe – dark chestnut. Seed scales 16 mm long and 13 mm wide, longitudinally finely striate, entire, less often finely dentate, rounded at the upper margin. Seeds ovoid, acute, 4-5 mm long, brownish on one side with noticeable light spots and gray-brown on the other side. Wing oblong-oblanceolate, 10-15 mm long. Cones ripen at the end of September. Begins to fruit at 8-10 years. Produces viable seeds every year.

Subspecies: Picea schrenkiana subsp. schrenkiana, Picea schrenkiana subsp. tianschanica [synonym: Picea tianschanica Rupr.]

Ornamental forms: f. globosa

Hardiness zone: 5a

Site: tolerates shade, prefers light. Not demanding of soil fertility, but requires moist air and soil. Grows on humus-carbonate soils as well as on acidic brown soils. Good drainage is necessary.

Planting: Does not like transplanting. Soil mix: turf and leaf soil, peat, sand in ratio 2:2:1:1. Drainage made of crushed brick, layer 15-20 cm. Planting depth: 50-70 cm. Root collar at ground level. Recommended spacing between plants – 2-3 m.

Care: after planting, fertilize with 100-150 g of nitroammophoska. In dry periods it is recommended to water daily with 10-12 L per plant. It is also desirable to sprinkle the crown. Loosen the soil to a depth of 5-6 cm; peat is not removed but mixed with the soil. Young seedlings need to be covered with conifer boughs for the winter. In young age it needs protection from spring sun; for this you can throw a non-woven fabric over the tree in 2 layers or install special protective shields on the southern side.

Pruning: It is recommended to pinch dominant shoots and shorten lateral shoots during growth. In youth it can be formed as a hedge.

Diseases: Schütte, snow Schütte, fusariosis, stem and root rot, bark necrosis, canker (wound cancer), cone rust, spruce vertun.

Pests: spruce leafroller, spider mite, Sitka spruce aphid.

Propagation: by seeds, cuttings, grafting or layering. Without treatment winter cuttings do not root. Seed germination 90%. Permissible seed storage period – 4 years. For good germination it is recommended to stratify at +1°C for 1-2 months. Rooting of cuttings 30%.

Conservation status: under protection.

Uses: most ornamental in solitary and group plantings, looks good in garden-park compositions, and also for hedges. Produces high-quality timber; the bark contains a large amount of tannins. Plays a soil-protective and water-protective role, can be used to stabilize mountain slopes.