Arborvitae vs New Zealand Flax Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Arborvitae

Arborvitae

Thuja occidentalis

VS
New Zealand Flax

New Zealand Flax

Phormium tenax

Arborvitae

Arborvitae

Thuja occidentalis

Thuja occidentalis, commonly known as American Arborvitae, is a coniferous evergreen tree or shrub. It typically grows outdoors to a height of 30-60 feet, forming a dense, pyramidal shape. The foliage consists of scale-like leaves arranged in flattened sprays. While valued for its use in hedges, screens, and ornamental plantings in landscapes, it is not naturally suited for indoor environments due to its high light and humidity requirements and large size. People grow it for its attractive foliage, fast growth, and tolerance of various soil conditions.

Cupressaceae Eastern North America
✨ Features: Provides year-round greenery and privacy. Attracts birds.
📖 Read Complete Arborvitae Guide
New Zealand Flax

New Zealand Flax

Phormium tenax

Phormium tenax, commonly known as New Zealand Flax, is a large, evergreen perennial plant forming clumps of long, strap-like leaves. It's native to New Zealand and is primarily an outdoor plant, valued for its dramatic architectural form and fiber production. The leaves can grow up to 3 meters long and come in various colors, from green to bronze and variegated forms. While it can be grown indoors, it requires very bright light and significant space, making it challenging for most homes. People grow it for its striking appearance in gardens and landscapes.

Asphodelaceae New Zealand
✨ Features: Dramatic architectural form, fiber production (traditionally used by Maori people)
📖 Read Complete New Zealand Flax Guide

Quick Plant Comparison

Feature Arborvitae New Zealand Flax
Light Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth. Full sun to partial shade outdoors. Indoors, requires extremely bright, direct sunlight for several hours daily.
Watering Every 1-2 weeks, depending on weather and soil drainage. Every 1-2 weeks, depending on light and temperature. Less frequent in winter.
Humidity 40-60% 30-50%
Temperature 10-24°C 10-27°C
Care Level Expert Expert
Growth Rate Moderate Moderate
Max Height Rarely grown indoors; outdoors 9-18 meters 1-2 meters indoors (much larger outdoors)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining, slightly acidic soil. A mix of loam, sand, and peat moss is suitable. Well-draining soil is crucial. A mix of potting soil, sand, and perlite is suitable.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 30 minutes monthly (outdoor) 30 minutes weekly

🔬 Botanical Information — Comparing These Plants

Arborvitae

Scientific Name Thuja occidentalis
Family Cupressaceae
Native To Eastern North America
Also Known As American Arborvitae, Eastern Arborvitae, White Cedar, Swamp Cedar
Leaves Scale-like, flattened, and arranged in overlapping sprays. Typically bright green, but can turn bronze in winter. Aromatic when crushed.
Flowers Inconspicuous flowers that are rarely seen. Primarily grown for its foliage.

New Zealand Flax

Scientific Name Phormium tenax
Family Asphodelaceae
Native To New Zealand
Also Known As New Zealand Flax, Harakeke
Leaves Long, strap-like leaves that can grow up to 3 meters long. The leaves are stiff and leathery, with a smooth texture. Colors range from green to bronze, red, and variegated forms.
Flowers Rarely flowers indoors. Outdoors, it produces tall flower stalks with reddish-brown flowers in summer.

📏 Size & Growth — Plant Comparison

Arborvitae

Height Rarely grown indoors; outdoors 9-18 meters
Spread Rarely grown indoors; outdoors 1-4 meters
Growth Rate Moderate
Growth Pattern Upright, pyramidal or conical shape. Can be maintained as a hedge through regular pruning. Branches are densely packed with scale-like foliage.

New Zealand Flax

Height 1-2 meters indoors (much larger outdoors)
Spread 1-1.5 meters indoors (spreads via rhizomes)
Growth Rate Moderate
Growth Pattern Forms a dense clump of upright, arching leaves. Spreads via rhizomes, potentially becoming quite large over time.

🌱 Propagation — Comparing Plant Growth

Arborvitae

Methods: Stem cuttings, Seed

Difficulty: Moderate

Tips: Take semi-hardwood cuttings in late summer. Dip in rooting hormone and plant in well-draining soil. Keep moist and provide indirect light.

New Zealand Flax

Methods: Division, Seed

Difficulty: Moderate

Tips: Division is best done in spring. Carefully separate the rhizomes and plant them in well-draining soil. Seeds can be sown in spring after soaking them in water for 24 hours.

✨ Benefits & Features — Comparing Plant Value

Arborvitae

Its dense, evergreen foliage provides year-round privacy and screening. It is relatively fast-growing compared to other evergreens. The scale-like leaves are aromatic when crushed.

  • ✓ Provides privacy and screening.
  • ✓ Offers year-round greenery.
  • ✓ Attracts birds and wildlife.
  • ✓ Relatively low-maintenance once established.
  • ✓ Can be used to create formal hedges or natural screens.
  • ⚠️ Toxic to pets

New Zealand Flax

New Zealand Flax is known for its long, strap-like leaves and dramatic architectural form. It is a versatile plant that can be used in a variety of landscaping applications. The plant's fibers were traditionally used by the Maori people for weaving.

  • ✓ Adds a dramatic architectural element to indoor or outdoor spaces.
  • ✓ Provides a bold statement with its striking foliage.
  • ✓ Offers a connection to New Zealand's natural heritage.
  • ✓ Can be used as a privacy screen outdoors.
  • ✓ Relatively low-maintenance once established (outdoors).
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Arborvitae

Repotting Not applicable for indoor growing; outdoor plants should be transplanted when young if needed.
Pruning Prune to maintain shape and remove dead or damaged branches. Best done in late winter or early spring.
Fertilizing Slow-release fertilizer in spring. Avoid over-fertilizing.
Seasonal Care Spring: Fertilize. Summer: Monitor for pests and water regularly. Fall: Water deeply before winter. Winter: Protect from heavy snow and wind.

New Zealand Flax

Repotting Every 1-2 years, or as needed, especially if the plant becomes root-bound. Use a larger pot with fresh well-draining soil.
Pruning Remove dead or damaged leaves as needed. Trim back to maintain shape.
Fertilizing Balanced liquid fertilizer diluted to half strength every 2-3 months during the growing season (spring and summer).
Seasonal Care In winter, reduce watering and ensure the plant receives as much light as possible. In summer, provide adequate moisture and consider moving the plant outdoors if possible.

🌞 Light Requirements

Arborvitae

Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal growth.

Low light tolerant: ❌ No

New Zealand Flax

Full sun to partial shade outdoors. Indoors, requires extremely bright, direct sunlight for several hours daily.

Low light tolerant: ❌ No

💧 Watering Needs

Arborvitae

Water deeply when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. In containers, ensure proper drainage. Signs of underwatering include browning foliage and drooping. Overwatering symptoms include yellowing leaves and a musty smell from the soil.

New Zealand Flax

Water thoroughly when the top inch of soil is dry. Overwatering can lead to root rot, especially indoors. Allow the soil to dry slightly between waterings. Signs of underwatering include drooping leaves; overwatering includes yellowing leaves and a soggy soil.

🌡️ Temperature & Humidity

Arborvitae

Temperature: 10-24°C

Humidity: 40-60%

New Zealand Flax

Temperature: 10-27°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Arborvitae

Arborvitae

Thuja occidentalis
Care: Expert Time: 30 minutes monthly (outdoor) Beginner: No

Landscapers and gardeners looking for a fast-growing evergreen for hedges, screens, or ornamental plantings in outdoor settings.

✅ Choose This Plant If...

  • You need a fast-growing evergreen screen or hedge for your yard.
  • You want to attract birds to your garden.
  • You have well-draining soil and plenty of sunlight.
  • You live in a climate with cold winters and hot summers.
  • You want a low-maintenance plant once established outdoors.

❌ Skip This Plant If...

  • You live in an apartment or have limited outdoor space.
  • You have pets that might ingest the foliage.
  • You cannot provide at least 6 hours of direct sunlight daily.
  • You are looking for an easy indoor plant.
📍 Ideal Location: Outdoor gardens, landscapes, or large containers on patios.
🎨 Style: Traditional, Natural, Formal
🏠 Apartment Friendly: No
⚠️ The foliage contains thujone, which can cause gastrointestinal upset, vomiting, diarrhea, and dermatitis in dogs, cats, and horses. Large quantities must be ingested to cause severe symptoms.
New Zealand Flax

New Zealand Flax

Phormium tenax
Care: Expert Time: 30 minutes weekly Beginner: No

Experienced plant enthusiasts with very bright indoor spaces or those looking for a striking outdoor plant.

✅ Choose This Plant If...

  • You have a very bright, sunny indoor space and want a statement plant.
  • You live in a mild climate and want a striking evergreen for your garden.
  • You appreciate plants with architectural form and interesting foliage.
  • You are interested in the traditional uses of plants and their cultural significance.
  • You are an experienced plant owner looking for a challenging indoor plant project.

❌ Skip This Plant If...

  • You have limited indoor space.
  • You have pets that might ingest the plant.
  • You struggle to provide bright, direct sunlight.
  • You are a beginner plant owner.
  • You tend to overwater your plants.
📍 Ideal Location: Sunroom, conservatory, or a very bright south-facing window.
🎨 Style: Modern, Tropical, Architectural
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, New Zealand Flax is toxic to dogs, cats, and horses. The toxic principle is glycosides. Symptoms include vomiting, diarrhea, and depression.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

🌿

Both plants have similar basic care requirements but differ in appearance and specific needs. Compare plants carefully to find the best fit for your space.

💡 Pro Tips For Comparing These Plants

Arborvitae Care Tips

American Arborvitae is primarily an outdoor plant and is very difficult to maintain indoors due to its high light and humidity requirements. It needs full sun and well-draining soil. Indoor cultivation is not recommended.

  • Plant in well-draining soil to prevent root rot.
  • Water deeply during dry periods, especially in the first year.
  • Prune regularly to maintain shape and density.
  • Protect from heavy snow and wind in winter.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: Protect from heavy snow and wind to prevent branch breakage and winter burn. Water deeply in the fall before the ground freezes.
☀️ Summer: Water regularly during dry periods. Monitor for pests and diseases. Mulch to retain moisture and suppress weeds.

New Zealand Flax Care Tips

New Zealand Flax is primarily an outdoor plant and requires expert care to thrive indoors. It needs very bright light, well-draining soil, and careful watering to avoid root rot. Due to its size and light requirements, it's not well-suited for most indoor environments.

  • Provide at least 6 hours of direct sunlight daily indoors.
  • Ensure excellent drainage to prevent root rot.
  • Water deeply but infrequently, allowing the soil to dry slightly between waterings.
  • Fertilize regularly during the growing season.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: Reduce watering significantly. Ensure the plant receives as much light as possible. Protect from frost if grown outdoors in marginal climates.
☀️ Summer: Provide adequate moisture, especially during hot weather. Consider moving the plant outdoors to a sunny location if possible. Monitor for pests and diseases.

⚠️ Common Problems & Solutions — Plant Care Comparison

Arborvitae

Common Issues: Spider mites, bagworms, root rot, winter burn
Solutions: Spider mites: Insecticidal soap or neem oil. Bagworms: Handpick or use Bacillus thuringiensis (Bt). Root rot: Improve drainage and avoid overwatering. Winter burn: Provide wind protection and adequate watering in fall.

New Zealand Flax

Common Issues: Root rot, Scale insects, Mealybugs, Leaf spot
Solutions: Root rot: Improve drainage and reduce watering. | Scale insects: Wipe off with a damp cloth or use insecticidal soap. | Mealybugs: Treat with insecticidal soap or neem oil. | Leaf spot: Improve air circulation and remove affected leaves.

❓ Frequently Asked Questions — Comparing These Plants

Arborvitae

What are the light requirements for Arborvitae?

Arborvitae thrives in bright, indirect light. Direct sunlight can scorch its delicate foliage, so avoid placing it directly in front of south-facing windows. East- or west-facing windows provide optimal light conditions. If you notice the foliage becoming pale or sparse, it may indicate insufficient light. Supplement with artificial grow lights if natural light is limited, especially during winter months. Rotate the plant regularly to ensure all sides receive adequate light. Monitor the plant’s growth and adjust its position as needed to maintain healthy foliage. Insufficient light can lead to legginess and poor growth.

How do I care for Arborvitae?

Indoor Arborvitae require bright, indirect light; avoid direct sunlight, which can scorch the foliage. Water thoroughly when the top inch of soil feels dry, ensuring proper drainage to prevent root rot. Maintain moderate humidity levels; consider using a humidifier or placing the pot on a pebble tray. Fertilize sparingly during the growing season (spring and summer) with a balanced, slow-release fertilizer. Repot every 2-3 years or when the plant becomes root-bound, using a well-draining potting mix. Prune regularly to maintain shape and remove any dead or yellowing foliage. Provide adequate air circulation to prevent fungal diseases. Monitor for pests such as spider mites and aphids, and treat promptly with insecticidal soap. Keep the plant in a stable temperature range, avoiding extreme fluctuations. Rotate the plant occasionally to ensure even growth. Dust leaves regularly to allow for better light absorption.

How do I propagate Arborvitae?

Arborvitae can be propagated through stem cuttings or air layering.

New Zealand Flax

What are the light requirements for New Zealand Flax?

New Zealand Flax prefers bright, indirect light. Placing it near an east-facing window is ideal, as it receives gentle morning sun. A south-facing window can also work, but be sure to filter the light with a sheer curtain to prevent leaf burn. Insufficient light can lead to leggy growth and faded leaf colors. Rotate the plant regularly to ensure even light exposure on all sides. If natural light is limited, supplement with grow lights to maintain healthy growth. Consider the intensity and duration of light, aiming for at least 6 hours of bright, indirect light per day. Consistent light exposure is crucial for vibrant foliage.

How do I care for New Zealand Flax?

New Zealand Flax thrives with bright, indirect light; avoid direct sunlight to prevent scorching. Water thoroughly when the top inch of soil feels dry, ensuring good drainage to prevent root rot. Maintain moderate humidity levels. Ideal temperatures range from 60-80°F (15-27°C). Fertilize during the growing season (spring and summer) with a balanced liquid fertilizer diluted to half strength every 4-6 weeks. Repot every 2-3 years or when the plant becomes root-bound, using a well-draining potting mix. Prune dead or damaged leaves regularly to maintain appearance and promote healthy growth. Provide adequate ventilation to prevent fungal diseases. Monitor for pests such as spider mites and treat promptly. Stable conditions are key to success.

How do I propagate New Zealand Flax?

New Zealand Flax can be propagated through stem cuttings or division. For stem cuttings, take a healthy cutting from a mature plant, ensuring it has at least one node. Remove the lower leaves and place the cutting in water or directly into a well-draining potting mix. Keep the cutting moist and in a warm, bright location until roots develop. For division, carefully separate the root ball of a mature plant into smaller sections, ensuring each section has healthy roots and foliage. Plant each section in its own pot with well-draining potting mix. Water thoroughly and keep in a warm, bright location. Propagation is best done in spring or summer. Use rooting hormone to improve success rates.

Last updated: May 11, 2026 — Plant care data reviewed and verified by our editorial team.