Emerald Tree plants, often referred to as Emerald Green Arborvitae (Thuja occidentalis 'Smaragd'), are popular evergreen shrubs or small trees known for their vibrant green foliage and conical shape. Their growth rate is a key consideration for gardeners and landscapers, as it determines how quickly they can achieve desired heights or fill spaces in a garden.
The growth rate of Emerald Tree plants is classified as moderate. On average, these plants grow between 6 to 12 inches (15 to 30 cm) per year under optimal conditions. However, growth can vary depending on factors such as climate, soil quality, water availability, and care practices.
Several factors impact how fast Emerald Tree plants grow:
Emerald Tree plants thrive in USDA hardiness zones 3-7. They prefer full sun to partial shade, with at least 6 hours of direct sunlight daily. Insufficient light can slow growth, while excessive heat or drought may stress the plant.
Well-drained, slightly acidic to neutral soil (pH 6.0–7.0) is ideal. Poorly drained or compacted soil can stunt root development and reduce growth rates. Adding organic matter can improve soil structure and nutrient availability.
Consistent moisture is crucial, especially during the first few years. Overwatering or underwatering can hinder growth. A balanced, slow-release fertilizer applied in early spring can promote healthier and faster growth.
Light pruning in early spring can encourage denser growth, but excessive pruning may slow overall growth. Regular inspection for pests (e.g., spider mites) and diseases (e.g., root rot) is essential to maintain vigor.
Understanding the growth stages helps in managing expectations:
During the first two years, growth may appear slower as the plant focuses on root development. Proper watering and mulching are critical to support this phase.
Once established, the plant enters a more active growth phase, adding 6–12 inches annually. Foliage becomes denser, and the conical shape becomes more pronounced.
At maturity, Emerald Tree plants can reach heights of 10–15 feet (3–4.5 meters) with a spread of 3–4 feet (0.9–1.2 meters). Growth may slow slightly as the plant allocates energy to maintenance rather than expansion.
Emerald Tree plants grow slower than some Arborvitae cultivars (e.g., Green Giant, which grows 3+ feet per year) but faster than dwarf varieties. Their moderate growth makes them suitable for hedges or screens where a balance between speed and manageability is desired.
To ensure optimal growth:
