Thuja occidentalis 'Smaragd' (Emerald Green Arborvitae)

Thuja occidentalis 'Smaragd' provides shelter and nesting opportunities for small birds and wildlife. It is often used by birds as a refuge, especially during cold months. The dense foliage also makes it a protective habitat for certain species of insects.

Thuja occidentalis 'Smaragd', is a true year-round evergreen that provides consistent structure and vibrant color in the landscape across all four seasons. In spring, the plant pushes out soft, bright green new growth at the tips of its dense, vertical branches, subtly refreshing its appearance. Through the summer months, this growth matures into the rich, lush emerald tone the variety is famous for—retaining a clean, formal look with minimal pruning. As fall arrives, the foliage remains full and green, offering stability and backdrop color as surrounding perennials begin to fade. In winter, unlike many arborvitae cultivars that bronze or dull, 'Smaragd' maintains its deep green hue remarkably well, even in northern climates. This makes it an excellent choice for cold-weather structure, privacy, and seasonal interest, especially when deciduous plants are bare. Its consistent appearance and minimal seasonal change make it a favorite for low-maintenance, evergreen design.

Narrow Privacy Screens & Hedges – Perfect for small yards or along fences

Foundation Plantings – Adds height and evergreen structure near homes or buildings

Formal Gardens – Beautiful when used in symmetrical plantings or rows

Accent Specimen – Great for framing entries or as a vertical accent

Container Planting – Can be grown in large pots with proper winter protection

Winter Interest – Holds color better than most arborvitaes in cold weather

The leaves are scale-like, dense, and evergreen, maintaining a bright emerald green color throughout the year, even in winter. The foliage forms in flattened sprays, which gives the tree a feathery yet structured appearance.

• Flowering Seasons: While this plant is not known for its flowers, it produces small, inconspicuous flowers in spring.
• Flower Description: The flowers are tiny, often yellowish-brown and unremarkable, usually appearing in clusters. They are not a major ornamental feature.

• Planting Time: Best planted in spring or early fall to allow roots to establish before extreme weather conditions.
• Soil: Prefers well-drained, fertile soil but is adaptable to a range of soil types, including clay and sandy soils. Slightly acidic to neutral pH is ideal.
• Spacing: Space trees 3 to 4 feet apart when planting for a privacy hedge, allowing enough room for mature growth without overcrowding.

Minimal pruning is required. You can trim lightly in early spring or late fall to maintain its shape or remove any damaged branches. Avoid heavy pruning as it can disrupt the natural form of the tree.

Thuja occidentalis 'Smaragd' requires consistent moisture, particularly during its first few years. Water regularly to keep the soil evenly moist, but avoid waterlogging. Once established, it is moderately drought-tolerant, though occasional deep watering is recommended during dry periods.

Full sun to partial shade. It thrives in full sun, receiving at least 6 hours of direct sunlight per day. However, it can tolerate some shade, though growth may be slower in lower light conditions.

While not harvested for food or flowers, Thuja 'Smaragd' provides ornamental foliage that can be used for decorative purposes, especially around the holidays.

Fertilize in early spring with a slow-release, balanced fertilizer to promote healthy growth. If soil conditions are poor, adding compost or organic matter can help boost nutrient levels.

• Mulching: Applying a layer of mulch around the base helps retain soil moisture, regulate temperature, and suppress weeds.
• Winter Care: Although cold-hardy, applying an anti-desiccant spray before winter can prevent winter burn in very cold climates.

Thuja occidentalis 'Smaragd' is wind-pollinated, and though it produces small, non-showy flowers, pollination is not a primary concern for gardeners as it is grown primarily for its foliage and form.

🌸 Flowering Perennials & Shrubs:

• Hydrangea paniculata ‘Limelight’ – Cone-shaped blooms contrast beautifully with vertical form
  
• Echinacea purpurea (Coneflower) – Purple blooms add upright color
  
• Heuchera ‘Palace Purple’ – Deep burgundy foliage offers rich contrast
  

🌾 Ornamental Grasses & Groundcovers:

• Festuca glauca ‘Elijah Blue’ – Cool-toned grass echoes the foliage color
  
• Carex ‘Ice Dance’ – Variegated, soft groundcover for shaded areas
  
• Sedum ‘Autumn Joy’ – Adds structure and late-season blooms
  

🌳 Evergreens & Structural Companions:

• Buxus (Boxwood) – Neat, rounded shape balances Smaragd’s columnar habit
  
• Spiraea ‘Goldmound’ – Bright gold foliage adds seasonal color contrast
  
• Ilex crenata ‘Sky Pencil’ – Pairs well for layered height variation