Tree · Cupressaceae
Japanese Cedar
Cryptomeria japonica
Give it rich, moist soil and a little shelter from winter wind, and Japanese cedar will reward you by growing 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 goes by the name sugi and stands in tall, dignified rows around temple grounds. Do not let the name mislead you. This tree belongs to the cypress and redwood family rather than to the true cedars, and it stands alone in its own genus. In the garden you will love its soft, feathery look, with awl-shaped needles spiraling around every shoot.
Here is a tree with genuine presence, and it is easier to grow than its size suggests. Given room, it rises 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 so much character. It handles cold right down to -20°F (-29°C), which carries it comfortably through USDA zones 5 to 9.
Most gardeners choose one of the named cultivars over the wild form, and you have plenty to pick from. Some stay as tidy dwarf globes that are perfect for a small bed, while the full-size selections grow into fast, dense screens. Whichever you plant, it simply asks for steady moisture and a spot out of the harshest wind, and from there it looks after itself and lets you relax.
Care
The short version: give it 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, and you are set.
Light
Japanese cedar is happiest in full sun, where the canopy grows dense and even and looks its best. It will get by in partial sun or light shade too, though a shadier home leaves the growth a little thinner and looser.
Water
Keep the soil consistently moist, especially while the tree is young, and try not to let it dry out. Watering every 7 to 14 days works well in most gardens, and an established tree will forgive you a brief dry spell. The one thing it truly cannot cope with is real drought.
Soil
Plant it in rich, deep, moist, well-drained loam that leans acidic, ideally a pH of 5.0 to 6.5. You want soil that holds moisture without turning waterlogged, so mix in some organic matter if your ground is heavy or thin.
Temperature
This is a wonderfully 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 with ease, though drying winter wind does more harm to it than the cold ever will.
Humidity
Average outdoor humidity is all it asks for, so there is no number for you to track. Steady soil moisture matters far more to this tree than anything 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 going overboard only encourages soft, weak growth, so there is no need to fuss.
Pruning
Happily, Japanese cedar needs little pruning. Clip out any dead, damaged, or winter-burned shoots in spring, and that is generally the whole job. It also takes shearing beautifully, which is why it makes such a clean screen or hedge when you want one.
Repotting
Most Japanese cedars grow in the ground and never need repotting at all. If yours lives in a container, repot rarely, and let roots circling the pot, water rushing straight through, or stalled new growth be your gentle cue that it is time.
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 away from buildings and other trees, or if space is tight, simply step down to a dwarf cultivar with no regrets.
When to plant
Because Japanese cedar is an evergreen conifer, you have no sowing season to chase and no harvest to time, which takes a lot of pressure off. Plant it in spring or early fall, while the soil is warm and moisture comes easily, so the roots enjoy a full stretch of mild weather before they meet 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 handful of troubles it does run into tend to show up in the foliage. Most are only cosmetic and clear up on their own with the season, so there is little to worry about. Match what you are seeing to the notes below before you decide whether anything needs doing.
Winter foliage looks bronzed or scorched, and that is usually fine
Take a breath, because this is almost always just winter bronzing, a natural color change that plenty of cultivars pass through before they green up again come spring. You will notice the worst of it on the windward side, where cold wind draws moisture from the needles faster than frozen roots can send it back up. Give the tree a bit of shelter from that wind, water it well before the ground freezes, and trim away any shoots that stay brown once new growth returns.
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
Spotted needles and a little twig dieback
This tends to be leaf spot and leaf blight fungi like Cercospora and Pestalotiopsis, which settle into the still, damp air of the lower inner branches. They usually take hold when a tree is already stressed, so a plant struggling with a hard site or a dry spell is the one most likely to catch it. The good news is that it looks worse than it is, so snip out the affected twigs, open the canopy so air moves freely, and keep your tree healthy, and it will come through fine.
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
Here is welcome news for pet owners: Japanese cedar is not toxic. It appears on no poison lists, and your animals can share the garden with it in complete safety. The one thing to keep in mind is the foliage itself, since the needles are stiff and sharply pointed.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
You can let your cat wander near this tree with an easy mind, because it holds no known toxin. If a curious cat nibbles a little foliage, the worst you might see is some drooling or a passing tummy upset, just as with any coarse plant.
Dogs None
Your dog is perfectly safe around Japanese cedar, which sits on no poison list at all. Should a pup chew a fallen sprig, you might notice a brief, mild bout of stomach trouble and nothing worse.
Horses Safe
Horses have nothing to fear from this tree, as it carries no toxic threat. The stiff, awl-shaped needles are prickly enough that most horses simply leave it be.
Rabbits Safe
Rabbits are in no danger from this conifer, and no harmful compound has ever been recorded in it. The prickly foliage rarely tempts them to take a bite in the first place.
Livestock Safe
Cattle, goats, and sheep can graze happily nearby with no risk of poisoning. Those sharp, resinous needles make the tree an unappealing snack, so grazing is unlikely anyway.
Birds Safe
Birds come to no harm here, and many happily shelter in the tree's thick evergreen cover. Nothing in the foliage or cones will hurt them.
People Safe
Japanese cedar is safe for you and your family to plant and handle, though those pointed needles can prick bare skin. It has no edible part, so it is grown for shade and screening rather than for the kitchen.
Foliage is harmless to handle, though needles are sharply pointed and awl-shaped.
Varieties
The straight species grows quite large, so most gardeners happily choose a cultivar that fits the space they have. These are the ones you are most likely to come across.
Yoshino
If winter bronzing worries you, this vigorous, fast grower keeps its blue-green color right through the cold with very little bronzing, and it reaches about 30 to 40 feet.
Black Dragon
A friendly dwarf with very dark green foliage held in an upright, dense, slightly ragged pyramid that adds real character to a small bed.
Globosa Nana
A gentle, slow-growing rounded dwarf shrub of about 2 to 4 feet whose bluish-green needles warm to a rusty-red cast once winter sets in.
Sekkan-sugi
A cheerful pick grown for the creamy-yellow new growth that lights up the tips of its branches.
Radicans
A fast, narrow pyramid dressed in rich blue-green foliage, which makes it an easy favorite for a living screen.
How to propagate
You can raise Japanese cedar from seed, cuttings, or layering, and picking a method comes down to whether you want a true copy of a named cultivar or just a few more trees to enjoy.
SeedModerate
Sow in fall or spring after cold stratification · Several months to germinate; years to reach landscape size
Growing Japanese cedar from seed is well within your reach, so long as you give the seed a cold stratification and sow in fall or spring. Just be kind to yourself about the wait, since germination takes several months and the young trees need years to reach landscape size. One thing to know: seedlings come out variable, so named cultivars will not breed true this way.
Stem cuttingsModerate
Semi-hardwood cuttings in late summer to fall · Several weeks to months to root
When you have your heart set on an exact copy of a named cultivar, cuttings are your friend. Take semi-hardwood cuttings from late summer into fall, dip them in rooting hormone, and keep them humid while they settle in and root over the following weeks to months.
LayeringModerate
Spring · One or more seasons
This is the easygoing method, since low branches will happily root wherever they rest against the soil. Pin one down in spring, let it grow its own roots, and give it a season or more before you cut the new plant free.
Myths
Japanese cedar is a true cedar.
The name can fool you, but this tree has no kinship with the true cedars of the genus Cedrus. Cryptomeria keeps its own genus inside the cypress and redwood family, Cupressaceae, and that is where it truly belongs. Read the common name as a charming quirk, not a guide to its family.