Cryptomeria japonica
Cryptomeria japonica
Japanese cedar
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Taxonomy
Family Cupressaceae · Genus Cryptomeria
Description
Cryptomeria japonica, or Japanese cedar, is a graceful, evergreen conifer with soft, feathery foliage that stays lush year-round. It forms a naturally pyramidal shape, takes well to pruning for hedges, and comes in many handsome cultivars—from towering screens to compact garden forms.
Common Names
Japanese cedarSugiJapanese red-cedarCryptomeria
Context
nativeRegion
Endemic to Japan (Honshu, Shikoku, Kyushu, Yakushima); widely planted across East Asia.
usdaZones
5–9
companionPlants
Azalea (Rhododendron), Camellia, Pieris japonica, Japanese maple (Acer palmatum), Hosta, Ferns, Hydrangea
culturalUses
Important Japanese timber tree for construction and cooperage; common in shrine and temple plantings; used for hedges, windbreaks, reforestation, and bonsai. Pollen is a notable spring allergen in Japan.
Care
Care Requirements
LightFull sun for best density; tolerates light shade, especially in hotter climates.
WateringKeep evenly moist during establishment (first 2–3 years). Deep water in prolonged drought; avoid waterlogging.
SoilMoist, well-drained, acidic to neutral loam; tolerates clay if drainage is improved. Mulch to keep roots cool.
FertilizerApply a balanced, slow‑release, acid-forming fertilizer in early spring; avoid heavy nitrogen late in summer. Compost mulch annually.
HumidityAverage outdoor humidity; benefits from consistent moisture and shelter from drying winter winds.
TemperatureHardy in USDA 5–9. Prefers cool to mild summers; protect from hot, dry winds. Can bronze in winter cold; withstands near -20°F once established.
Growth & Life Cycle
HabitEvergreen conifer with pyramidal to columnar form; dense, feathery foliage; many dwarf and compact cultivars.
Mature SizeTypically 50–70 ft tall and 20–30 ft wide; wild specimens can be much taller. Dwarf cultivars range 6–15 ft.
Growth RateModerate to fast, often 1–2 ft/year when young under good conditions.
BloomingNot showy; male pollen cones in late winter to early spring, small round female cones mature by late season.
DormancyEvergreen; growth slows in winter. Some cultivars bronze or purple in cold weather.
Propagation
MethodsSeed (cold stratify), Semi-hardwood cuttings, Hardwood cuttings, Grafting (for named cultivars)
DifficultyModerate
Best SeasonSemi-hardwood cuttings in late summer–early autumn; graft in late winter; sow stratified seed in spring.
Maintenance & Notes
PruningLow maintenance. Lightly shape or thin in late winter/early spring. Avoid hard cuts into old bare wood. Shear hedges after spring flush.
RepottingIn-ground trees don’t need repotting. Containers/bonsai: repot every 2–3 years in spring; refresh 1/3 of mix annually; prune roots lightly.
Pests & DiseasesGenerally resilient. Possible issues: spider mites in hot, dry weather; scale, bagworms. Fungal needle blights (e.g., Cercospora) and root rot in poorly drained soils; winter burn from desiccating winds.
ToxicityGenerally non-toxic to people and pets; pollen can trigger allergies.
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