Thujopsis dolabrata, Japanese false arborvitae
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Coniferous Trees

Thujopsis dolabrata

Japanese false arborvitae

Cupressaceae

Japan (Honshu, Shikoku, Kyushu, Kii Peninsula); montane forests at 980–6,600 feet (300–2,000 m)

At a Glance

TypeTree
HabitUpright
FoliageEvergreen
Height20–50 feet (6–15 m)
Width10–20 feet (3–6 m)
Maturity30 years

Growing Zones

USDA Hardiness Zones

5 - 8
Zone 5
Zone 6
Zone 7
Zone 8
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Deer Resistant
Maintenancevery low

Overview

Thujopsis dolabrata is a slow-growing, long-lived evergreen conifer native to Japan, the sole species in its genus. Trees reach 20–50 feet (6–15 m) tall and 10–20 feet (3–6 m) wide in cultivation over many decades; growth rate is 6–12 inches (15–30 cm) per year. The habit is broadly pyramidal with tiered, somewhat horizontal to slightly pendulous branches. Foliage is the defining feature: scale-like leaves are unusually large — up to 0.3 inch (8 mm) long — thick, glossy, and shell-shaped, arranged in flat, overlapping, fan-shaped sprays. The upper surface is dark, glossy green; the underside displays conspicuous white butterfly-shaped or hourglass-shaped stomatal marks that flash white when branches move. This bold, coarse-textured foliage clearly distinguishes T. dolabrata from the finer-scaled Thuja species. Cones are 0.4–0.6 inch (10–15 mm) long, globular to ovoid, with thick woody scales. The species performs best in cool, moist, partly shaded conditions and declines in hot, dry exposure. It is not drought-tolerant.

Native Range

Thujopsis dolabrata is native to Japan (Honshu, Shikoku, Kyushu, and the Kii Peninsula), in montane forests at elevations of 980–6,600 feet (300–2,000 m), typically in cool, humid conditions. It is not native to the Pacific Northwest.

Suggested Uses

Planted as a specimen in woodland gardens, shaded residential borders, and Japanese-inspired gardens, spaced 10–15 feet (3–4.6 m) from adjacent plants. The bold, coarse foliage texture contrasts effectively with fine-textured companions. Best suited to partly shaded, cool, consistently moist sites in west-side Pacific Northwest conditions. Not suitable for dry east-side sites or exposed windy locations.

How to Identify

Thujopsis dolabrata is identified by its unusually large, thick, glossy, shell-shaped scale leaves arranged in flat sprays, dark green above with conspicuous white butterfly- or hourglass-shaped stomatal marks on the undersides — more boldly marked than any other Cupressaceae in common cultivation. Distinguished from Thuja plicata by the much larger, thicker, coarser scale leaves and the bolder white underside markings; distinguished from Platycladus by the rounded (not flattened) foliage segments.

Appearance

Size & Dimensions

Height20' - 50'
Width/Spread10' - 20'

Reaches mature size in approximately 30 years

Colors

Flower Colors

brown

Foliage Colors

dark green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~3 weeks
J
F
M
A
M
J
J
A
S
O
N
D
Spring
Male and female cones are on the same plant (monoecious). Male strobili are small, dark red-brown, at shoot tips, releasing pollen in March–April. Female cones are 0.4–0.6 inch (10–15 mm) long, globular to ovoid, with 6–8 thick woody scales tipped with a small hook, ripening from green to brown in autumn.

Detailed Descriptions

Flower Description

dark red-brown (male strobili)

Foliage Description

dark glossy green above, bold white butterfly-shaped marks below

Growing Conditions

Sun Requirements

Partial Shade
Full Shade
Requires 2-6 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.0 - 6.5(Acidic)
357912
Soil Types
loamsand
Drainage
well drained

Water & Climate

Water Needs

High

Frost Tolerance

hardy

Time to Maturity

20–40 years

Care & Maintenance

Care Guide

Water weekly during the first two growing seasons; established trees require consistent moisture and do not tolerate drought. Prefers cool, moist, well-drained soils in partial shade; declines in hot, dry, or exposed sites. Performs best on the west side of the Cascades in Pacific Northwest conditions. Unlike Thuja plicata, this species is not suitable for hot, dry inland sites. No serious pest or disease problems in cool, moist conditions. Growth rate is slow — allow many years for the plant to reach landscape significance.

Pruning

No pruning required. The naturally tiered, pyramidal form develops without intervention. Pruning disrupts the tiered branching pattern and is rarely beneficial. Remove dead branches at any time.

Maintenance Level

very low

⚠️ Toxicity Warning

Non-toxic
Thujopsis dolabrata (Japanese false arborvitae) - Identification & Care Guide | PlantRef