Thuja western (lat.Thuja occidentalis) - an evergreen coniferous tree of the Cypress family, naturally grows in the eastern regions of North America, in East Asia and reaches 30 meters in height.
It has small (2-4 mm) green scaly needles that live 2-3 years and fall off with small branches. Small (7-12 mm) ovoid cones are composed of thin scales and contain two flattened seeds.
Thanks to selection in culture, it is distributed throughout all continents in different climatic zones. Weeping, dwarf, variegated forms (about 120 varieties) grow in the gardens of Europe, including Ukraine and Russia. Due to its frost resistance, and most importantly - resistance to urban conditions, thuja western is widely used in garden and park plantings.
Popular varieties of western thuja:
Thuja western golden-pointed Aureospicata (Thuja occidentalis Aureospicata) is a fast-growing variety with a wide-conical crown. At the age of 10, it reaches a height of 3 m. The needles are dark green, young shoots are golden. Prefers moist and fertile soils. In a row landing - an interval of 0.8-1 m.
Thuja western columnar Columna (Thuja occidentalis Columna) is the best of the columnar forms. It is widely used in landscaping. Slow growth, with annual growth 15-20 cm in height and 3-5 cm in width. Reaches a height of 5-8 m, crown diameter - 1.5 m. Dense, scaly crown of dark green color, does not change color in winter. Shade-tolerant, frost-resistant.
Thuja western spherical Golden Globe (Thuja occidentalis Golden Globe) is one of the most popular spherical varieties of thuja with a pale yellow color of needles. Growth is slow, at the age of 10 it reaches a diameter of 0.8-1 m. Prefers fertile soils. Recommended for small gardens.
Thuja western Hoseri (Thuja occidentalis Hoseri) is another spherical variety with dark green needles. Dwarf variety, at the age of 10, the height of the tree is about 40-50 cm. Prefers fertile soils, it is recommended for use in small gardens, rockeries, rock gardens.
Thuja western Smaragd (Thuja occidentalis Smaragd) is the most popular variety of thuja. Grows up to 5-6 m, crown diameter 1.5-1.7 m. Annual growth is 10-15 cm in height and 4-5 cm in width. At the age of 10, it reaches 2.5-3 m. The crown is of the correct narrow pyramidal shape, the color of the needles is green all year round. Well pruned. Frost and shade tolerant. Prefers well-drained fertile loams. Resistant to urban conditions. It is used in single and group plantings to create a hedge.
Purchase of seedlings. When choosing seedlings, it is recommended to pay special attention to the condition of the root system and crown. The roots should be either in a container or in a damp earthy coma. The crown should look healthy, free from damage and dry shoots.
Location and landing. Prefers places protected from the wind. Grows well in partial shade, in highly shaded areas the crown thins.
It is undemanding to the soil, but grows better on loamy and sandy loam soils. An important condition is that the soil must be permeable, therefore, when planting in heavy soil, drainage from sand and broken brick (15-20 cm) is required. The size of the planting pit depends on the size of the earthy coma on the roots of the plant - the depth is about 60-80 cm. The composition of the planting soil mixture: 2 parts of leaf or sod land, 1 part of peat and 1 part of sand. Often 50-100 g of nitroammofoska or Kemira-wagon are added to the soil mixture. The trunk circle is mulched with peat, wood chips and control that the root collar is at the level of the soil.
Watering. Thuja responds very favorably to sprinkling (watering from a hose with a splitter), because its lush crown evaporates a lot of moisture. Recommended frequency of sprinkling: 2-3 times a week in open areas and once a week in protected areas. Seedlings in the first month after planting also need abundant weekly watering: from 10 to 30 liters of water per 1 plant, depending on its size.
Loosening, mulching. Sawdust, peat with a layer of 5-7 cm are used as mulch. If the soil is too dense, it must be periodically loosened. The loosening depth should not exceed 8-10 cm.
Top dressing. If complex fertilizer was applied during planting, then the thuja should be fed only after 2 years with Kemiroi-universal at the rate of 80-100 g per sq. M. Fertilizer is applied in spring, during the growing season. Before winter, it is impossible to feed so that the young shoots growing into growth do not freeze.
Trimming and shaping. Tui well tolerate haircuts and formative pruning. In spring it is recommended to remove dry, damaged and diseased branches, in summer - to cut no more than one third of the length of the shoots.
Reproduction and grafting. Seed propagation is most effective. For this, 2-3 year old ripe cones are selected. Vegetative propagation is also practiced: by cuttings and layering.
Diseases and pests. Thuja western is more susceptible to fungal diseases and invasion of pests than thuja eastern.
In early spring, the scales on individual shoots may turn yellow, after which the shoots turn brown and fall off. The disease is caused by a fungus, control measures - removal of diseased shoots, once every 2 weeks from July to October, spraying the crown with a 0.2% solution of foundationazole.
The accumulation of insects causes yellowing and dropping of the needles. Antio or karbofos is used against thuja false shield and thuja aphids.
Plants in winter. Mature trees are hardy enough. It is advisable to protect young plantings in the first two or three years from frost and winter-spring sunburn. The plants are covered with kraft paper, spruce branches or other suitable covering material.
Interesting facts: In Canada, fresh thuja branches are used as brooms with a pleasant smell. In folk medicine, infusions and decoctions from the leaves and bark of thuja are used as a diaphoretic, diuretic, lactogenous and laxative.