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How to Grow Japanese Cedar – Cryptomeria

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Cryptomeria —often called Japanese Cryptomeria–is a graceful conifer that grows eventually into a skyline tree, however, there are several dwarf cultivars that are low-growing and well-suited for even small gardens. 

Cryptomeria has soft bright green to bluish green foliage during the growing season. Needle-like leaves can turn brownish-purple in cold weather. Branches are slightly pendulous; the species tree grow pyramidal towards maturity. Straight trunks are in red-brown bark peeling in strips. Dwarf cultivars are effective accents in a conifer collection or in a large rock garden.

Cryptomeria is a genus of just one (possibly two) species. Cryptomeria is native to conifer forests in China and Japan. 

Cryptomeria japonica
Cryptomeria japonica

Get to know Cryptomeria 

  • Plant type: Evergreen shrub or tree
  • Growing zones and range: Zones 6 to 9  
  • Hardiness: Hardy to Zone 6 
  • Height and width: Species Ctyptomeria japonica can grow to 50 feet ((15m) tall and half as wide; shrub cultivars grow from 2.5-5 feet (.8-1.5m) high, 2.5-4.5 feet (.8-1.4m) wide. 
  • Growth rate: Medium
  • Form and habit: Compact, dome-shaped, pyramidal; eventually skyline tree with a straight columnar trunk, thin red-brown bark peeling in strips; branches, slightly pendulous.
  • Foliage: Narrowly, wedge-shaped light to dark green needlelike leaves .3-.8 inch (.8-1.8cm) long, which point forward in spirals around shoots; becomes bluish as the shrub matures and turns rust-red in cold weather; roundish, red-brown cones .8-1 inch (2-2.5cm) wide.  
  • Fruits: Globular cones .5-1 inch (1.3-2.5cm) long, dark brown.   
  • Uses: Use larger forms as specimen planting; use smaller forms as foundation plants, background for deciduous shrubs and for perennials; sometimes used in closely planted goes for a Japanese garden effect.  
  • Common name: Japanese Cryptomeria, Japanese cedar
  • Botanical name: Cryptomeria 
  • Family name: Taxodiaceae
  • Origin: Forests in China and Japan

Where to plant Cryptomeria 

  • Plant Cryptomeria in full sun or high shade. 
  • Cryptomeria needs protection from wind  
  • Plant Cryptomeria in rich, deeply dug, well-drained, moist, somewhat acidic soil; pH 6.0 to 6.7.  
Dwarf Japanese cedar, Cryptomeria japonica 'Globosa Nana'
Dwarf Japanese cedar, Cryptomeria japonica ‘Globosa Nana’

When to plant Cryptomeria 

  • Set container-grown Cryptomeria in the garden in spring or autumn.
  • Sow seed in containers in spring.

Planting and spacing Cryptomeria 

  • Space Cryptomeria according to its width at maturity; from 5 feet to 25 feet (1.5-10m) apart.
  • Set container-grown Cryptomeria into humus-rich, light, moist soil that is on the acid side, pH 6.0 to 6.7. It adapts to heavy clay soils.  

How to water and feed Cryptomeria 

  • Give Cryptomeria regular water.  
  • Feed Cryptomeria with an all-purpose organic fertilizer in spring.

How to prune and care for Cryptomeria 

  • Pruning season for Cryptomeria is after growth is completed. 
  • Some species, like the dwarf Japanese cedar, do not need pruning.  

Cryptomeria pests and diseases 

  • Needle necrosis, branch dieback, and root rot can occur in young plants.
  • Nematodes can cause stunting of Cryptomeria.
A Japanese cedar tree, Cryptomeria japonica
A Japanese cedar tree, Cryptomeria japonica

Cryptomeria propagation 

  • Sow seed in containers in a cold frame or in a seedbed in spring.
  • Root ripewood cuttings in late summer or early autumn.

Cryptomeria varieties to grow 

  • Cryptomeria japonica, this species Cryptomeria can grow to be a tall, elegant tree with a straight trunk; it matures into a pyramidal or conical form that reaches 50 feet (15m) tall and 25 feet (7.5m) wide; branches are layered from its pointed top to the ground. There are several smaller cultivars list below.
  • ‘Globosa Nana’, grows slowly to a height of 2-5 feet (.6-1.5m). It’s an excellent evergreen for rock gardens and shrub borders and works well as a background plant in large perennial borders. It succeeds in seacoast gardens if protected from the worst of the wind.  
  • ‘Elegans’, Plume Cedar, Plume Cryptomeria, quite unlike species. Feathery, grayish-green, soft-textured foliage. Turns coppery red or purplish in winter. Grows slowly into a broad-based, dense pyramid, 20-60 feet (6.1-18.3m) high. Trunks on old trees may lean or curve. For Oriental effect, prune out some branches to give tiered look. For the most effective display, give it space. Makes a good formal hedge if trimmed every August.  
  • ‘Benjamin Franklin’, a non-dwarf cultivar with blue-green foliage grows 30-40 feet (9.1-12.2m) tall.  
  • ‘Lobbii Nana’ (‘Lobbii’). Upright, dwarf, very slow to 4 feet (1.2m). Foliage dark green.  
  • ‘Pygmea’ (‘Nana’), Dwarf Cryptomeria, bushy dwarf 1.5-2 feet (3.8m) high, 2.5 feet (6.4m) wide. Dark green, needle-like leaves, twisted branches.  
  • ‘Vilmoriniana’, slow-growing dwarf 1-2 feet (2.5-5.1m). Fluffy gray-green foliage turns bronze in late fall and winter. Rock garden or container plant.  

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