Serbian Spruce 'Nana'

Serbian Spruce 'Nana' (Picea omorika Nana) – a cultivar of Serbian spruce. The cultivar was developed in 1930 in Boskoop (the Netherlands) based on the GOUDKADE mutation.

It is a slow-growing coniferous small tree with a broad-conical dense crown up to 3 m in height and up to 1.5 m in diameter. In the first years it grows without a clearly defined trunk; later a leader shoot appears and the spruce changes shape from globular to broad-conical. Growth rate 5-10 cm per year. Shoots short, stiff. Bark dark brown, scaly.

Needles sparse, radially arranged on the shoot, yellow-green above, bluish beneath, reaching 7-8 mm in length and 1.5 mm in width.

Cones light brown, ovoid, up to 5 cm in length.

Hardiness zone: 4-7 (-28°C).

Location: Light-loving, but tolerates light partial shade. Grows poorly on very acidic and compacted soils; in such places the needles begin to yellow. Smoke and gas tolerance is moderate. Demands ambient humidity, but tolerates dryness better than the common spruce.

Soil: recommended pH 4.5-6.5. Prefers moderately dry to moist soils; generally undemanding, but does not tolerate compacted soils with waterlogging.

Planting: The optimal time for planting is late April to late June. Spacing between plants in group plantings – 2-3 m. Planting hole depth – 60-70 cm. The root collar should remain at ground level. Soil mix: sod and leaf soil, peat and sand in a ratio of 2:2:1:1. The bottom of the hole should be filled with drainage of crushed brick and sand to a thickness of 15-20 cm.

Care: After planting, fertilization with 100-150 g of nitroammophoska can be applied. In dry periods it is recommended to water at least once a week with 10-12 L per plant. Loosening is done 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.

Pruning: Extensive pruning is permissible if you use the spruce as a hedge. For normal use, only dead and diseased branches are pruned.

Diseases: shutte, snow shutte, fusariosis, stem and root rot, bark necrosis, canker (wound cancer), cone rust, spruce vertun. Suffers less from spring burn than other cultivars of Canadian spruce.

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

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

Usage: effective in parterres, as solitary and group plantings, in rockeries and heather gardens.