Ayan spruce

Synonyms: Abies jezoensis Siebold & Zucc., Picea ajanensis Fisch. ex Trautv. & C.A.Mey., Picea hondoensis Mayr, Picea jezoensis var. Hondoensis, Picea komarovii V. N. Vassil, Ель иезская, Ель йезонская, Ель камчатская, Ель Комарова, Ель мелкосемянная, Ель хоккайдская, Пихта аянская

Ayan spruce – a species of evergreen trees of the genus Spruce (family Pinaceae). In the wild it occurs in the Far East, in the northeastern part of the Korean Peninsula, the northeastern part of China, in Japan (Hokkaido and isolated in central Honshu), in Russia (the Sikhote-Alin Mountains, on Sakhalin, the southern Kuril Islands, on Kamchatka), and less frequently on the western coast of the Sea of Okhotsk.

It prefers places with cool, rainy summers; therefore in the southern part of its range it grows in mountains, where it rises to 500 m and up to the timberline. In the northern part it grows at lower elevations but does not occur farther than 400 km from the ocean.

In cultivation since 1861. Lifespan 350-400 (500) years.

Superficially resembles Sitka spruce or Norway spruce. It is a tall, slender and attractive tree reaching 40-50 m in height, trunk diameter up to 100-120 cm. Slow-growing when young, later the growth rate becomes moderate. Crown regular conical or pyramidal, single-topped. Branching whorled. Branches thin, stiff, strong. Bark dark gray, smooth when young, later peeling off in rounded plates. Shoots pale yellow-brown or yellow-green.

The needles are a distinctive species trait: flat, up to 2 cm long, on fertile shoots angled, slightly curved, short-pointed, arranged spirally. On the upper side the needles are dark green, beneath bright glaucous from the stomatal lines, densely appressed to the shoot, which distinguishes it from other species. They remain on the tree for up to 10 years.

Cones light brown, 3.5 to 8 cm long, pendulous, ovoid-cylindrical, slightly glossy. Scales leathery, loosely fitting, elliptical or oblong-elliptical, thin, with an emarginate or wavy-toothed, often truncate margin. Seeds reach 2.5-3 mm in length. Seed wing 7-11.5 mm long.

Siebold and Zuccarini, "Flora Japonica, Sectio Prima", 1870.

Two subspecies are recognized: Picea jezoensis subsp. Jezoensis (variety Picea jezoensis subsp. jezoensis var. komarovii) and Picea jezoensis subsp. Hondoensis.

Hardiness zone: 5a

Location: Light-demanding but shade-tolerant. Does not tolerate changes in air humidity or soil waterlogging. Demanding of soil, prefers fresh, moderately moist loams. Can grow on gravelly and rocky soils. Prone to windthrow when growing singly. Does not tolerate air pollution.

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

Care: after planting, apply 100-150 g of nitroammophoska. In dry periods water at least once a week with 10-12 L per plant. Loosen soil to a depth of 5-6 cm; do not remove peat, mix it with the soil. Young seedlings require covering with spruce boughs for winter protection.

Pruning: poorly tolerates pruning. Usually only sanitary pruning is performed. Regular pinching of dominant shoots and shortening of lateral shoots during growth can be practiced.

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

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

Propagation: by grafting onto Norway spruce, by cuttings and by seed. Seeds germinate in the year of sowing; 2-3 months stratification accelerates germination.

Uses: used to create contrast groups with bluish-gray foliage. Looks attractive against birches or other deciduous trees. Can be used for shelterbelts and forest plantings; effectively reduces noise levels.