Thuja ‘Smaragd’ (Emerald Green Arborvitae)
Thuja ‘Smaragd’, commonly known as Emerald Green Arborvitae, is a premium evergreen conifer valued for its narrow, upright form and rich green foliage. It is widely used in formal landscapes, screening, and architectural planting where a clean, vertical structure is required.
Its naturally compact, columnar shape makes it one of the most popular choices for creating neat hedges, avenues, and feature plantings without extensive shaping.
Key Specifications
Botanical name: Thuja occidentalis ‘Smaragd’
Common name: Emerald Green Arborvitae
Plant type: Evergreen conifer
Mature height: 4 to 6 metres
Mature width: 1 to 1.5 metres
Typical hedge height: 2 to 4 metres
Typical hedge width: 0.8 to 1.2 metres
Growth rate: Moderate
Time to maturity: Approximately 5 to 8 years
Growth Habit and Structure
Thuja ‘Smaragd’ is known for its naturally narrow, columnar growth.
Forms a dense, upright silhouette
Maintains a consistent shape without heavy pruning
Branches grow tightly, creating a full, uniform appearance
This strong vertical habit makes it ideal for structured planting where space is limited but height is desired.
Foliage Characteristics
The foliage is soft, fine-textured, and highly ornamental.
Features include:
Bright emerald green colour
Dense, scale-like leaves
Year-round colour retention
The foliage remains vibrant throughout the seasons, providing consistent greenery and visual structure.
Growth and Establishment
Thuja ‘Smaragd’ establishes steadily and develops into a refined, structured plant over time.
Early stage:
Focuses on root development with gradual top growth
2–3 years:
Noticeable height increase and thickening of form
5–8 years:
Reaches mature size with a dense, fully developed shape
Its controlled growth makes it easy to manage in formal designs.
Light Requirements
Performs best in full sun to light shade.
Full sun:
Promotes the densest growth and strongest colour
Light shade:
Maintains good form with slightly softer density
Suitable for a wide range of garden positions.
Watering Requirements
Responds well to consistent watering, particularly during establishment.
During establishment:
Water regularly to support root development
Once established:
Water weekly or as needed depending on conditions
In warmer periods:
Additional watering supports steady, healthy growth
Consistent moisture helps maintain dense foliage and overall plant quality.
Soil Preferences
Prefers well-drained soil with good organic content.
Suitable for:
Loam soils
Sandy soils
Improved clay soils
Performs best when planted in well-prepared soil with good drainage.
Pruning and Maintenance
Low-maintenance and naturally tidy.
Minimal pruning required due to natural shape
Light trimming can be done to refine form if needed
Ideal for formal planting with minimal upkeep
Maintains a clean, architectural appearance with little effort.
Fertilising
Benefits from occasional feeding to support growth and colour.
Apply a slow-release fertiliser during the growing season
Organic mulch improves soil condition and moisture retention
Feeding enhances foliage density and colour.
Spacing Guide
For hedging:
Plant 0.8 to 1.2 metres apart
Closer spacing creates a tighter, more formal hedge
Wider spacing suits individual feature planting
Landscaping Uses
Thuja ‘Smaragd’ is widely used for:
Formal hedging
Privacy screening
Feature columns in garden design
Entryway planting
Avenues and symmetrical layouts
Its narrow form makes it ideal for tight spaces and structured landscapes.
Longevity and Performance
A long-lasting evergreen that maintains its shape and colour over time.
Provides consistent structure and greenery
Suitable for long-term landscape projects
Retains its refined appearance with minimal maintenance
Summary
Thuja ‘Smaragd’ is a narrow, upright evergreen conifer that grows to approximately 4–6 metres tall and 1–1.5 metres wide. With a moderate growth rate and a naturally dense, columnar form, it is ideal for hedging, screening, and architectural planting.
Its vibrant green foliage, clean shape, and low maintenance requirements make it a premium choice for creating structured, elegant landscapes.
