The Thuja occidentalis ‘Emerald Green’ arborvitae stands as a beloved choice for homeowners and landscapers alike, cherished for its vibrant green foliage, naturally elegant conical shape, and its unparalleled ability to create dense, living privacy screens. Its popularity often brings forth a common and crucial question: how long does it truly take for these magnificent evergreens to reach their full, mature potential? Understanding the growth trajectory of your Emerald Green arborvitae is essential for planning your landscape and managing expectations. This article will delve into the various factors that influence their growth rate, demystify what “maturity” means for this specific cultivar, and provide a realistic timeline so you can anticipate when your green screen will finally be complete.
Understanding Thuja Emerald Green’s growth habits
The Emerald Green arborvitae, sometimes referred to as ‘Smaragd’, is celebrated for its manageable growth rate and distinctive characteristics. Unlike some faster-growing, more unruly evergreens, the Emerald Green offers a more controlled and predictable development. It typically exhibits a medium growth rate, which translates to an average increase of about 6 to 12 inches per year under optimal conditions. Its natural inclination is to grow in a narrow, columnar fashion, maintaining a relatively compact footprint even at maturity.
When we talk about “maturity” for this plant, we are generally referring to its maximum potential height and width, as well as the density of its foliage. A mature Emerald Green arborvitae usually reaches a height of 10 to 15 feet and a spread of 3 to 4 feet. However, it is important to distinguish between reaching its ultimate biological size and achieving “maturity” in the context of its intended purpose, such as a privacy hedge. For a privacy screen, you might consider it mature once it reaches a sufficient height and density to block views, which can often occur before it hits its absolute maximum biological dimensions.
Key factors influencing growth speed
The rate at which your Emerald Green arborvitae grows and reaches maturity is not solely predetermined; it is significantly influenced by a variety of environmental and care-related factors. Providing the right conditions can help your plants thrive and accelerate their journey to maturity, while suboptimal conditions can hinder their progress.
- Soil quality: Emerald Green arborvitae prefers rich, moist, and well-drained soil. Heavy clay soils or extremely sandy soils can impede root development and nutrient uptake. Amending your soil with organic matter, like compost, can vastly improve its structure and fertility.
- Sunlight exposure: These evergreens perform best in full sun to partial shade, ideally receiving at least 6 hours of direct sunlight per day. While they can tolerate some shade, too little light can result in slower growth, sparser foliage, and a less vibrant color.
- Watering regimen: Consistent moisture is crucial, especially during the first few years after planting. Young plants need regular, deep watering to establish a strong root system. Drought stress can severely slow growth and even lead to irreversible damage. Conversely, waterlogging can cause root rot.
- Fertilization: A balanced, slow-release evergreen fertilizer applied in early spring can provide essential nutrients, encouraging robust growth. However, over-fertilization can be detrimental, so always follow product instructions carefully.
- Climate and hardiness zone: Emerald Green arborvitae is hardy in USDA zones 3-7. Growing them outside their ideal climate range, whether in excessively cold or hot conditions, can stress the plants and slow their growth significantly.
- Initial plant size: Naturally, starting with a larger, more established plant will give you a head start towards your desired mature height. While smaller plants are often more budget-friendly, they will take longer to reach the same size.
The typical timeline to maturity
While various factors can influence the exact timing, we can outline a general timeline for Thuja Emerald Green arborvitae to reach a functional maturity, especially when planted as a privacy screen.
| Stage | Approximate Timeline (Under Ideal Conditions) | Key Characteristics and Growth |
|---|---|---|
| Establishment Phase | 1-2 years | Focus on root development. Visible top growth might be minimal (0-6 inches/year). The plant is settling into its new environment. |
| Rapid Growth Phase | 3-7 years | Significant increase in height (6-12 inches/year) and beginning to fill out laterally. The plant starts to take on its characteristic dense form. |
| Nearing Functional Maturity | 7-10 years | Reaching a height of 8-12 feet and good density for a privacy screen. Growth rate may start to slightly reduce, but the plant continues to thicken. |
| Full Biological Maturity | 10-15+ years | Reaching full potential height (10-15 feet) and maximum width (3-4 feet). Growth becomes very slow, focusing on maintaining health and density. |
It is important to remember that these are averages. A plant receiving perfect care in an ideal climate might reach functional maturity closer to the 7-year mark, while one experiencing less-than-ideal conditions could take 10 years or more. Patience is truly a virtue when cultivating these beautiful evergreens.
Accelerating growth and maintaining health
While you cannot force an Emerald Green arborvitae to grow beyond its genetic potential, you can certainly optimize its environment to encourage its fastest and healthiest development. Adhering to best practices in planting and ongoing care is key.
- Proper planting: Dig a hole that is twice as wide as the root ball and just as deep. Ensure the top of the root ball is level with or slightly above the surrounding soil to prevent waterlogging. Space plants appropriately (typically 2-3 feet apart for a dense hedge) to allow for air circulation and root expansion.
- Consistent watering: Especially during the first two years, deep watering once or twice a week is crucial, particularly during dry spells. Check soil moisture before watering. Once established, they are more drought-tolerant but will still benefit from irrigation during extended dry periods.
- Mulching: Apply a 2-3 inch layer of organic mulch (like shredded bark or wood chips) around the base of the plants, keeping it a few inches away from the trunk. Mulch helps retain soil moisture, regulate soil temperature, and suppress competing weeds, all of which contribute to healthier growth.
- Strategic pruning: Minimal pruning is generally needed for Emerald Green due to its naturally neat form. If pruning is desired to encourage density or maintain a specific shape, do so lightly in late winter or early spring before new growth emerges. Avoid heavy pruning into old wood, as it may not regenerate. Regular tip pruning can encourage bushier growth.
- Pest and disease monitoring: Regularly inspect your plants for signs of pests (like bagworms or spider mites) or diseases. Early detection and appropriate treatment can prevent significant setbacks in growth and overall plant health.
Bringing your Emerald Green arborvitae to full, majestic maturity is a journey that typically spans several years, influenced by a delicate interplay of environmental conditions and consistent care. While there is no instant solution to achieving a dense privacy screen, understanding the plant’s growth habits and providing optimal conditions can significantly impact the timeline. From establishing a robust root system in the initial years to promoting lush foliage through proper watering, sunlight, and soil management, each step contributes to its eventual splendor. Remember that “maturity” can be a flexible term, often reached sooner for functional purposes like a privacy hedge than for its absolute biological potential.
Ultimately, growing Thuja Emerald Green arborvitae requires patience and dedication, but the reward is a truly magnificent, low-maintenance evergreen that provides year-round beauty and privacy. By focusing on the core principles of good horticultural care, you empower your plants to reach their full potential, transforming your landscape with their vibrant, stately presence for many years to come.
Image by: Logan Voss