Cryptomeria Radicans , commonly referred to as Radicans Japanese Cedar , is a cultivar of Cryptomeria japonica , the sole specie in the monotypic genus Cryptomeria . It belongs to the Cupressaceae household , which encompasses other conifers like cypresses , juniper bush , and sequoias . Despite its rough-cut name , it ’s not a unfeigned cedar ( genus Cedrus ) , but its wood and form align it with that aesthetic . Classified under the order Pinales , Cryptomeria is a gymnosperm , producing naked seeds in minuscule cones . The ‘ Radicans ’ cultivar is distinguished from the species by its specific development traits , though it apportion the same taxonomic stemma as a woody , needle - leave evergreen plant native to East Asia .

The history of Cryptomeria Radicans tie closely to its parent coinage , Cryptomeria japonica , which has been cherished in Japan for 100 as a timber tree and sanctified planting around shrines . While the species was enter to westerly horticulture in the 1840s , ‘ Radicans ’ emerged afterward as a cultivated variety , in all probability choose for its degenerate growth and denser drug abuse . Its growth is less documented than the species , but it gained traction in the U.S. and beyond during the 20th hundred as landscapers sought reliable evergreens for privacy and ornamentation . breed for resilience and esthetical appeal , it reflects the long - fend Japanese tradition of complicate Cryptomeria for pragmatic and visual purposes .

Cryptomeria japonica , the parent of ‘ Radicans ’ , is aboriginal to Japan ’s mountainous region and role of southern China , though its furious condition in China is debated . The ‘ Radicans ’ cultivar , however , is a product of horticultural selection , not find naturally . Since its origination to North America and Europe , it has been wide distributed through the nursery deal , prosper in temperate landscape painting rather than naturalise . Its culture traverse from suburban yards to commercial properties , with important use in the southeastern and westerly U.S. , where its adaptability to wide-ranging soil and climates radiate . shuttlecock and idle words do n’t spread it like invasives — it ’s a measured planting choice .

Cryptomeria Radicans stands out with its balmy , feathery , needle - similar foliage , spiraling around sprig in a obtuse , dark light-green cloak that chemise to a subtle bluish or bronze tincture in winter . Growing in a narrow-minded , pyramidic form , it reach 30–50 human foot tall and 10–20 feet wide at a brisk 3–4 feet per year , faster than many Cryptomeria cultivars . Its reddish - browned bark peels in sparse strip , adding texture , while little , circular cones ( about an in broad ) constellate the tip , though they ’re less salient than the foliage . Unlike some relatives , it resist hint blight and maintains a inviolable central leader , giving it a tidy , vertical silhouette without much pruning .

This cultivar flourishes in USDA Zones 5 to 9 , handle cold snaps down to -20 ° F ( -29 ° century ) and stick out temperate summer rut . It ’s most vigorous in Zones 6–8 , where winters are mild enough to avoid severe phonograph needle burn and summers are n’t oppressively humid . Well - drained , somewhat acidulous grease ( pH 5.5–6.5 ) suit it best , and it needs shelter from harsh winds in colder zone to stay lush . In hotter climates , partial tint can preclude stress , making it versatile across a broad swath of North America .

Cryptomeria Radicans is a landscape gardening dynamo , prized for its rapid ontogenesis and evergreen plant density . It ’s a top pick for privacy screen or windbreaks , with its wet , feathery leafage forming a living rampart when planted 8–10 feet apart — gross for close up neighbor or noise . As a specimen tree , its graceful Pyramids of Egypt shape anchors large yard or frames terrace , while its cervid resistance and down upkeep appeal to hands - off gardeners . In smaller space , it can describe private road or accent corners , though its stature demands room to stretch . The sonant texture and year - round color make it a standout , blending function with muted sophistication .

Cryptomeria Radicans: Cultivation

mood Compatibility

Cryptomeria Radicans thrives in USDA zone 5 to 9 , hold up first gear to -20 ° F ( -29 ° C ) and handling moderate summer heat . It performs best in Zones 6–8 , where winters are mild and summers avoid excessive humidness that strain its foliage .

Sunlight Requirements

Plant in full sun for maximum maturation and tightness — expect 3–4 foot of vertical addition yearly . It tolerates partial shade , especially in hot climate , where good afternoon protection prevent needle burn or drying out .

Soil Preferences

It opt well - drained , slightly acidic soils ( pH 5.5–6.5 ) , like loamy or sandy mixes . profound clay or alkaline term hinder root health , so amend with peat or compost to boost drain and sourness if needed .

lachrymation Needs

Keep grease evenly moist during the first two years to establish its shallow antecedent system of rules — piddle deep hebdomadary if rain is scarce . Once mature , it ’s moderately drouth - tolerant but benefit from occasional soaking during prolonged dry trance to maintain vigour .

Planting Time

other spring or downslope planting gives roots a question start before summer heat or deep freezing . head off midsummer transplants to minimize stress , though container - grown stemma can go in anytime frost is n’t impending .

Spacing

Space 8–10 foot apart for privacy screen or hedge , leveraging its 10–20 - ft fledged width . For standalone specimen , let 15–20 feet to showcase its 30–50 - foot height without crowding neighbors .

Fertilization

enforce a slow - release , acid - loving fertilizer ( like 10 - 10 - 10 or 4 - 3 - 4 ) in early spring before young growth kick in . One ignitor feeding annual suffices — overdo it risks floppy , weak branch that spoil its pixilated form .

mulch

Layer 2–3 column inch of constituent mulch ( pine barque or woods chips ) around the fundament to lock in moisture , cool roots , and deter Mary Jane . Keep mulch an inch from the trunk to nullify rot or pest issue .

Pruning Practices

Minimal pruning is needed thanks to its firm central drawing card and natural Pyramids of Egypt shape . cut beat or damage tips in late winter with clean shears — quash shearing intemperately , as it wo n’t regrow from old wood .

Pest Management

Monitor for spider mites , which dapple phonograph needle yellow in dry heat — savage them with urine or apply horticultural oil . scale leaf and bagworms may appear ; treat with insecticidal soap or hand - pick traveling bag early to keep impairment low .

Disease Prevention

Good drainage prevents beginning bunkum , while atmosphere circulation curbs leaf blight or fungal spot that brown needles in wet conditions . absent fallen debris and water at the base , not overhead , to trammel disease hazard .

Winter Protection

In Zones 5–6 , shield young plant from drying fart with gunny or anti - desiccant sprays — mature tree manage cold better but may bronze slightly . Brush off heavy snow to prevent branch deflexion , though it ’s sturdier than many conifers .

Propagation

spread via semi - hardwood cuttings in late summer — take 6–8 - inch tips , dip in rooting hormone , and root in a moist , sandy mix under high humidity . Seeds are rare and unreliable , so cutting are the go - to for this cultivar .