Picea PUNGENS 'GLAUCA'

Picea PUNGENS 'GLAUCA' - Colorado Blue Spruce, Blue Spruce.

Can be grown in bonsai style!

Spruce is a genus of coniferous evergreen trees in the Pinaceae family, comprising about 45 species distributed in cold and temperate climates, on sandy and rocky soils, and on marshy tracts of Eurasia and North America. The harsh mountainous terrains of China are considered the area of origin. The lifespan of the trees exceeds 200 years, and among them are long-lived individuals that survive to 500-600 years.

Tall trees with a beautiful crown reach 60 m (197 ft) in height and 1.5-2 m (5-6.6 ft) in diameter under optimal growing conditions. The straight trunks are covered with grey, uneven, thin, slightly peeling bark. Horizontal branches, nodding with time, form a pyramidal, low-hanging crown possessing high shade tolerance. Each shoot is densely covered with short, rigid leaves - needles. Needle blades of various green shades sit on leaf cushions. Annually, about one-seventh of the needles fall.

Lower branches resting against the ground can root and form layers. The root system of the plants undergoes cardinal changes with age. The taproot, which extracts nutrients, dies off over time. Meanwhile, surface roots spread actively to the sides. On well-drained soils, individual roots angle downward 50-70 cm (20-28 in).

At the age of 10-60 years, the plants begin to bear cones. Female cones, pointed upward, appear at the tips of branches. Smaller male cones are clustered in catkins in the middle of shoots. After pollination by wind-borne pollen, the cover scales close, and the female cones become pendulous. The red or violet coloration changes to brown. In mid-winter, the cones open. Thin winged seeds fall onto the snow-covered ground. They disperse significant distances from the parent plant.

In cultivation, low- and medium-growing species and cultivars with attractive needle coloration have gained the widest distribution. Low-growing cultivars are grown indoors as bonsai. For creating miniatures of various styles, this conifer representative is a unique and pliable material that produces remarkable compositions.

Colorado Spruce is a tree up to 15-30 m (50-100 ft) in height with a conical crown. The bark is grey-brown, thick, and furrowed. Young shoots are yellowish-brown or orange-brown, glabrous, and stiff. Male cones are brownish-brown; female cones are red, turning green upon ripening, and then brown. Flowering occurs in May to early June. Native to North America, where it grows in the Rocky Mountains at altitudes of 2000-3000 m (6500-9800 ft) above sea level. It is the most ornamental species.

It is desirable to stratify the seeds beforehand. Before planting, conifer seeds are soaked in a potassium permanganate solution, then for 24 hours in clean water, and then sown into sand at 0.5-1 cm (0.2-0.4 in). The container is kept from several days to 2 months in the cold at a temperature of 4-5 °C (39-41 °F). Under indoor conditions, seeds are placed in the refrigerator in late autumn or winter and planted in spring.

In March, the sowing is moved to a warm spot, moistened with a spray bottle, and germinated in light at a temperature of 21-22 °C (70-72 °F). Excessive moisture and drying out must be avoided. Seedlings appear in 2-3 weeks. Little spruces are carefully watered, fed twice with a weak solution of complete fertilizers, and the soil is lightly loosened.

In late May, seedlings are transplanted into open ground. Adding compost or mineral fertilizers to the planting holes is recommended. The soil is lightly firmed after planting the seedlings. A mini-greenhouse made of film or plastic bottles may be needed for a few days. Covers must be removed for ventilation and condensation removal.

Alternative method: Seeds are sown either in autumn or spring. They are pre-soaked for 24 hours in water, and after sowing, mulched with sawdust in a layer of 5-6 cm (2-2.4 in) in autumn and 2-3 cm (0.8-1.2 in) in spring. Seeds sown in spring germinate in two weeks; in autumn - after several months. Seedlings must be shaded. Young plantings are loosened shallowly, no deeper than 5-7 cm (2-2.8 in), because the root system is located close to the surface.

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Spruces are quite undemanding, drought-resistant, shade-tolerant, and mostly survive the harshest winters without loss; some species are fairly tolerant of excessive soil moisture and air pollution. They grow slowly, especially in the first years. They do not tolerate close groundwater and are vulnerable to trampling and soil compaction. They tolerate shearing well, after which they thicken considerably.

Mature spruces are fully frost-hardy and are not sheltered for winter. Young trees, especially in the first two years after planting, are mulched with peat or sawdust in a layer of 6-8 cm (2.4-3.1 in), and the needles of young seedlings of ornamental forms are protected from late frost and sunburn with spruce boughs or kraft paper. In spring, the peat is not removed but mixed with the soil, pulling it back from the root collar.

Early spring is considered the best time for planting on a plot. If multiple spruces are planned, planting pits measuring 60x80 cm (24x31 in) are spaced 2-3 m (6.6-10 ft) apart. A drainage layer is constructed of crushed brick and sand, and a mound of soil is poured. In the air, roots die in a matter of minutes, so the root ball should not be broken apart. Together with it, the plant is lowered into the pit without burying the root collar. The soil is compacted and carefully watered.

Cuttings or seeds are used for propagating trees on a site. Cuttings are neatly severed, the lower portion stripped of needles, and placed in a rooting stimulant. They are then planted in a mixture of sand, peat, and perlite at an angle. After watering, the plants are placed in a greenhouse or covered with film. At a temperature of 24-27 °C (75-81 °F), the twigs root rapidly.

The plant tolerates transplanting better than other conifer species: the main taproot stops its growth early, and lateral roots form a shallow root system, which, however, results in a weak ability of the trees to withstand wind pressure.

When growing for bonsai, seedling shaping begins when it reaches approximately 10-12 cm (4-4.7 in). After 2-3 years, the plant is repotted into a new container - a bonsai pot. Subsequently, the plant is repotted less frequently. At a more mature age (and growing bonsai takes decades), Spruce is repotted very rarely. Only formative pruning is performed on the miniature composition. For normal growth, complete fertilizers are applied regularly, keeping in mind that the dosage indicated on the package should be halved.