Japanese arborvitae

Family: Cupressaceae. In its native Japan, an evergreen, monoecious tree up to 35 m tall; in cultivation it is most often a shrub.

Twigs wide and flat, foliage scale-like, closely appressed to the shoot, glossy green above, with large white stomatal patches beneath. Spikes unisexual: male — on lateral shoots, terminal, solitary, cylindrical with 12–20 opposite stamens; female spikes — ovoid, solitary, terminal, composed of 8–10 transversely opposite, thick, fleshy scales, of which the upper and lower do not bear fruit. Cones woody, rounded, with upper ends curved outward. Seeds oval with two narrow, leathery wings.

Location: grows well in partial shade, but can also grow in open sites.

Soil: grows well on moist clay soils.

Planting: the best time to plant is spring (mid-April). Spacing in group plantings: 0.5–1.5 m depending on the age and height of the seedlings. Hole depth 60–70 cm. When planting, retain the root ball and do not disturb the mycorrhiza. Soil mix: peat-compost, topsoil (turf), sand in a ratio of 3:2:2. Drainage of broken brick 10–15 cm thick is desirable.

Care: when planting into the hole apply nitroammofoska (200–300 g) and mix thoroughly with the soil. After two years, regularly apply once each spring a complete fertilizer "Kemira Universal" (20 g/m2). Drought-tolerant; in hot, dry summers it is recommended to water and spray the plants, applying 8–10 L of water to each mature plant if the surface layer of soil has dried to 5 cm (this is determined by inserting fingers into the loose soil). In autumn before winter, the soil around the trunk (root circles) is dug to a spade's depth (once every three years). Mulch only young plantings with peat or wood chips to a depth of 5–7 cm. Pruning and trimming are done only to shape the crown, if necessary. Remove dead branches. Young seedlings are hardened off gradually. Cover them with conifer boughs for winter, and cover the root circles with leaves or peat to a depth of 12–15 cm; the latter is removed or raked away from the plants in spring. If planting was carried out late in autumn, seedlings are better wintered under pergamin (roofing felt) or fabric film, which should be fixed on a frame so they do not touch the plants. Mature plants are quite winter-hardy and do not change the color of their foliage in winter.

Propagation: by seeds, cuttings and by grafting onto Thuja.