Tree · Cupressaceae
Japanese Cedar
Cryptomeria japonica
Give it rich, moist soil and shelter from winter wind, and Japanese cedar grows into a towering evergreen spire.
Full sun
Every 7–14 days
USDA 5–9
50–70 ft · 15.2–21.3 m
Overview
Japanese cedar is the national tree of Japan, where it is known as sugi and lines temple grounds in tall, stately rows. The name is misleading. It belongs to the cypress and redwood family, not to the true cedars, and stands alone in its own genus. In the garden it reads as a soft, feathery evergreen conifer with awl-shaped needles spiraling around the shoots.
This is a tree with real presence. Left to grow, it climbs to 50 to 70 feet (15 to 21 m) with a broad pyramidal crown, and the reddish-brown bark peels away in long, shaggy strips that give the trunk its character. It takes the cold down to -20°F (-29°C), which carries it through USDA zones 5 to 9.
Most gardeners reach for one of the named cultivars rather than the wild form. Some stay as tidy dwarf globes for a small bed, while the full-size selections make fast, dense screens. Whatever the size, the tree asks for steady moisture and a spot out of the harshest wind, and it largely looks after itself from there.
Care
The short version: full sun to light shade, in rich, moist, acidic, well-drained soil that never dries out, and a planting spot sheltered from harsh, drying winter wind.
Light
Japanese cedar grows best in full sun, where the canopy stays dense and even. It will take partial sun or light shade, but a shadier spot leaves the growth thinner and looser.
Water
Keep the soil consistently moist, especially while the tree is young, and never let it dry out. Watering every 7 to 14 days suits most settings, though an established tree handles a brief dry spell. What it will not tolerate is real drought.
Soil
Plant in rich, deep, moist, well-drained loam on the acidic side, ideally a pH of 5.0 to 6.5. The soil needs to hold moisture without staying waterlogged, so work in organic matter on heavy or thin ground.
Temperature
This is a tough tree, hardy from -20°F to 100°F (-29°C to 38°C) across USDA zones 5 to 9. It shrugs off summer heat and deep winter cold alike, though drying winter wind does more harm than the cold itself.
Humidity
Average outdoor humidity is all it needs, so there is no number to track. Steady soil moisture matters far more than what the air is doing.
Feeding
Feed in spring with a balanced or acid-forming slow-release fertilizer made for evergreens. Once a season is plenty for a healthy tree, and overdoing it brings nothing but soft, weak growth.
Pruning
Japanese cedar needs little pruning. Clip out any dead, damaged, or winter-burned shoots in spring, and that is usually the whole job. It also takes shearing well, which is why it makes such a clean screen or hedge.
Repotting
Most Japanese cedars live in the ground and never need repotting. For one kept in a container, repot rarely, and watch for roots circling the pot, water rushing straight through, or stalled new growth as your cue.
Size & spacing
Plan for a tree that reaches 50 to 70 feet (15 to 21 m) tall with a spread of 20 to 30 feet (6 to 9 m). Give it that much room from buildings and other trees, or step down to a dwarf cultivar for a tighter spot.
When to plant
Japanese cedar is an evergreen conifer, so there is no sowing season to chase and no harvest to time. Plant it in spring or early fall, while the soil is warm and moisture is reliable, to give the roots a full stretch of mild weather before they face heat or hard cold.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring or early fall
- Harvest: Non-flowering; grown for evergreen foliage and form (cones mature in fall)
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
Japanese cedar is an easy, low-maintenance tree, and the few problems it runs into show up in the foliage. Most are cosmetic and pass with the season. Match what you see below before you decide whether to act.
Foliage turns bronze or scorched-looking over winter
Most of the time this is winter bronzing, a normal seasonal color shift that many cultivars run through before greening back up in spring. The worst patches show up on the windward side, where drying winter wind pulls moisture from the needles faster than frozen roots can replace it. Shelter the tree from harsh wind and send it into winter with moist soil, then prune out any shoots that stay brown once growth resumes.
Fix:
- Site plants where they are sheltered from harsh, drying winter winds
- Keep soil adequately moist going into winter
- Prune out shoots that fail to green up in spring
Brown spots on the needles with some twig dieback
Leaf spot and leaf blight fungi such as Cercospora and Pestalotiopsis settle into the lower, interior branches where the air stays still and damp. The trouble follows stress, so a tree fighting a poor site or drought is the one that picks it up. Cut out the affected twigs, open the canopy so air can move through, and keep the plant in good health, since the damage is almost always cosmetic rather than fatal.
Fix:
- Prune out and dispose of affected twigs and foliage
- Improve air circulation and avoid overhead wetting of foliage
- Maintain plant vigor with proper siting, water, and nutrition
Toxicity
Good news for pet owners: Japanese cedar is not toxic. It appears on no poison lists, and animals can live alongside it without risk. The only thing to mind is the foliage itself, since the needles are stiff and sharply pointed.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats can be around this tree without worry, since it carries no known toxin. A cat that nibbles the foliage might drool or have a brief stomach upset, the same as with any rough plant material.
Dogs None
Dogs are safe near Japanese cedar and it sits on no poison list. A pup that chews on a fallen sprig may get a passing bout of mild tummy trouble, nothing more.
Horses Safe
The tree poses no toxic threat to horses. Its needles are stiff and awl-shaped, so most horses leave it alone anyway.
Rabbits Safe
Rabbits are not at risk from this conifer. The prickly foliage rarely tempts them, and no harmful compound has been recorded.
Livestock Safe
Cattle, goats, and sheep can graze near it with no danger of poisoning. The sharp, resinous needles make it an unlikely snack to begin with.
Birds Safe
Birds come to no harm from the tree and often shelter in its dense evergreen cover. There is nothing toxic in the foliage or cones for them.
People Safe
Japanese cedar is safe for people to plant and handle, though the pointed needles can prick bare skin. There is no edible part, so it is grown for shade and screening rather than the table.
Foliage is harmless to handle, though needles are sharply pointed and awl-shaped.
Varieties
The straight species grows large, so most gardeners pick a cultivar to suit the space. These are the ones you will run into most often.
Yoshino
A fast, vigorous selection whose blue-green foliage holds its color through winter with far less bronzing, growing to about 30 to 40 feet.
Black Dragon
A dwarf with very dark green foliage and an upright, dense, slightly ragged pyramid shape.
Globosa Nana
A slow, rounded dwarf shrub of about 2 to 4 feet whose bluish-green needles take on a rusty-red cast in winter.
Sekkan-sugi
Grown for the creamy-yellow new growth that lights up the branch tips.
Radicans
A fast, narrow pyramid with rich blue-green foliage that makes it a favorite for screens.
How to propagate
You can raise Japanese cedar from seed, cuttings, or layering, and the method you choose depends on whether you want a true copy of a named cultivar or simply more trees.
SeedModerate
Sow in fall or spring after cold stratification · Several months to germinate; years to reach landscape size
You can grow Japanese cedar from seed sown in fall or spring after a cold stratification, but be patient, since germination takes several months and the trees need years to reach landscape size. The seedlings also come out variable, so named cultivars never breed true this way.
Stem cuttingsModerate
Semi-hardwood cuttings in late summer to fall · Several weeks to months to root
Cuttings are the route to take when you want a true copy of a named cultivar. Take semi-hardwood cuttings from late summer into fall, dip them in rooting hormone, and keep them humid while they root over the following weeks to months.
LayeringModerate
Spring · One or more seasons
Low branches will root where they touch the ground, so you can pin one down in spring and let it form its own roots. Expect to wait a season or more before the new plant is ready to cut free.
Myths
Japanese cedar is a true cedar.
Despite the name, it is no relation to the true cedars in the genus Cedrus. Cryptomeria stands in its own genus within the cypress and redwood family, Cupressaceae. The common name is a misnomer, not a clue to its family.