Emerald Green Arborvitae (Thuja occidentalis 'Smaragd') are the perfect choice for creating beautiful, low-maintenance privacy screens and hedges. These elegant evergreen trees grow 12-15 feet tall, maintain their vibrant emerald color year-round, and require minimal care once established. According to USDA Plant Hardiness Zone data, they thrive in zones 3-7, making them ideal for most North American climates.
Key Takeaways:
- Grows 1-2 feet per year when young, slowing to 6 inches annually at maturity
- Thrives in full sun to partial shade (6+ hours daily optimal)
- Water weekly with 1 inch of water once established
- Plant 3-4 feet apart for dense privacy screens
- Cold hardy to -40°F (Zone 3) when properly cared for
- Lifespan ranges from 25-150 years depending on conditions
Pro Tip: Use PlantJoy's smart watering calculator to get personalized irrigation recommendations based on your local climate and soil type.
Optimal Growing Conditions
Sunlight Requirements
Emerald Green Arborvitae need 6+ hours of direct sunlight daily for optimal growth. While they tolerate partial shade, insufficient light reduces foliage density. Dr. Emily Watkins, University of Vermont Extension Specialist, notes: 'In my 15 years studying conifers, I've found Emerald Greens in full sun develop 30% denser foliage compared to partially shaded specimens.'
Soil Preferences
These trees prefer moist, well-drained soil with neutral to slightly alkaline pH (6.0-8.0). Heavy clay soils require amendment with compost or sand for better drainage. A 2023 University of Minnesota study showed arborvitae in well-drained soil had 40% fewer disease issues.
Step-by-Step Planting Guide
When to Plant
Fall planting (September-October) is ideal as cooler temperatures reduce transplant stress. Spring planting (April-May) also works well in northern climates. Avoid summer planting when heat stress is highest.
How to Plant Emerald Green Arborvitae
- Choose a location with well-drained soil and full sun exposure
- Dig hole twice as wide and same depth as root ball
- Remove burlap or container, gently loosen roots
- Place tree ensuring root flare is level with soil surface
- Backfill halfway, water thoroughly to settle soil
- Complete backfilling, tamp gently to remove air pockets
- Water deeply and apply 2-3 inch mulch layer (keep away from trunk)
- Space trees 3-4 feet apart for privacy screens
PlantJoy Tip: Use our planting spacing calculator to visualize exactly how your hedge will look at maturity based on your specific measurements.
Watering and Maintenance
Watering Schedule
Newly planted trees need consistent moisture: water 2-3 times weekly for first 3 months. Established trees require 1 inch of water weekly, including rainfall. During drought, increase to 1.5 inches weekly.
Fertilizing
Arborvitae generally don't need fertilizer in good soil. If growth is slow, apply balanced 10-10-10 fertilizer in early spring. According to Oregon State University research, over-fertilization causes excessive growth that's more susceptible to winter damage.
Pruning and Shaping
Light pruning in early spring maintains shape and encourages dense growth. Always prune green foliage only—never cut back to brown wood as it won't regrow. For formal hedges, prune 2-3 times during growing season.
Seasonal Care Guide
Spring Care
- Inspect for winter damage and prune broken branches
- Apply fresh mulch layer to conserve moisture
- Fertilize if growth was poor previous year
- Monitor for early signs of pests or diseases
Winter Protection
In zones 3-4, protect young trees from heavy snow and ice. Wrap with burlap or use wooden frames to prevent branch breakage. Mature trees generally withstand winter conditions without protection.
Frequently Asked Questions
Pest Issues
Bagworms are the most serious pest—they can defoliate trees rapidly. Hand-pick bags in winter before eggs hatch. For severe infestations, use Bt (Bacillus thuringiensis) or spinosad treatments. Spider mites may appear during drought conditions.
Disease Prevention
Fungal diseases like tip blight and root rot occur in poorly drained soils. Improve drainage and avoid overhead watering. For existing infections, apply copper fungicide in early spring.
Winter Browning
Normal needle drops occur from interior branches each year. However, overall browning indicates winter desiccation—provide adequate fall watering and considers anti-desiccant sprays in exposed locations.
How fast do Emerald Green Arborvitae grow?
Young trees grow 1-2 feet annually, slowing to 6 inches per year at maturity. Most reach 12-15 feet height in 10-15 years. Growth rate depends on soil quality, sunlight, and moisture availability.
How close should I plant them for a privacy screen?
Space trees 3-4 feet apart for a dense screen. This allows proper air circulation while creating continuous coverage. Closer spacing (2-3 feet) creates faster screening but may increase disease risk.
Are Emerald Green Arborvitae deer resistant?
No—eastern arborvitae (Thuja occidentalis) are highly susceptible to deer browsing. Use physical barriers or deer repellents in areas with high deer populations. Western arborvitae varieties are more deer-resistant.
What's the difference between Emerald Green and Green Giant?
Green Giant grows faster (3+ feet annually) and larger (50-60 feet tall) but is less cold-hardy (Zone 5-7). Emerald Green stays smaller (12-15 feet) and is more cold-tolerant (Zone 3-7). Choose based on your space and climate needs.
Expert Tips from Landscape Professionals
'The key to perfect arborvitae hedges is consistent moisture during establishment,' says Michael Rodriguez, certified landscape architect. 'I recommend using drip irrigation for the first two years to ensure even watering.'
Dr. Sarah Chen adds: 'Many homeowners over-prune their arborvitae. Remember—these trees naturally form a pyramidal shape. Light, selective pruning maintains health without compromising their natural beauty.'
Important Safety Note
Emerald Green Arborvitae are toxic to humans and pets if ingested. The foliage contains thujone, which can cause stomach upset and neurological symptoms. Keep children and animals away from pruned branches and fallen needles.
Recommended PlantJoy Features
- Smart Watering Calculator: Get precise watering schedules based on your local weather
- Pest Identification: Upload photos of suspicious insects or damage for instant diagnosis
- Spacing Planner: Visualize how your hedge will look at maturity with our AR tool
- Seasonal Reminders: Receive timely care notifications for your specific plants
For more hedge planting ideas, check out our guide on Fast-Growing Privacy Trees for Quick Screening.
References and Further Reading:
- University of Minnesota Extension. (2023). 'Arborvitae Care and Management'. Retrieved from extension.umn.edu
- American Society of Horticultural Science. (2022). 'Winter Hardiness of Ornamental Conifers'. Journal of Environmental Horticulture, 40(2), 45-52.
- USDA Plant Hardiness Zone Map. (2023). Agricultural Research Service.
- Oregon State University Extension. (2024). 'Managing Bagworms in Landscape Trees'. EM 9212.
