tuija

Tuija is the Finnish common name for the evergreen conifer genus Thuja, in the family Cupressaceae. In horticulture, the term refers to species of Thuja cultivated for ornamental use, particularly Thuja occidentalis (Eastern arborvitae) and Thuja plicata (Western red cedar).

Thuja are slender to conical evergreens with flattened sprays of scale-like leaves. They form small woody cones about 1–2 cm long. In cultivation they are slow to moderate-growing; under suitable conditions they can reach several meters in height, with large specimens attaining tens of meters in the wild. They are widely used for hedges, screens, and windbreaks, and tolerate pruning for shaping.

They prefer well-drained soil and full sun to partial shade; hardy in temperate climates, but poorly tolerant of waterlogged soils. In winter they tolerate cold well but exposed plants may suffer; common pests include bagworms and scale insects; root rot and other fungal diseases can occur in wet soils. They are valued for their year-round foliage, form, and versatility in garden and landscape design.

Notable cultivars include Thuja occidentalis 'Smaragd' (Emerald). In Finland, Tuija is also a common female given name.