Japanese cedar (Cryptomeria japonica 'Spiralis')

Overview

Cryptomeria japonica ‘Spiralis’, commonly known as Japanese cedar, is a distinctive cultivar prized for its unique foliage texture. This cultivar features needles that twist spirally around the branchlets, creating a visual interest often referred to as granny’s ringlets. It offers year-round structure, transitioning from bright green to notable bronze tones during cold winters.

As a vigorous yet manageable needled evergreen, Cryptomeria japonica ‘Spiralis’ matures into a substantial specimen tree, though it grows much slower than the species in cultivation. Gardeners value this tree for its low maintenance profile and its capacity to serve as a dramatic vertical accent in the landscape.

While the standard Japanese cedar can grow massive, the ‘Spiralis’ cultivar provides an upright, somewhat conical silhouette, making it suitable where significant height is desired but width must be controlled. Its rich green, fragrant needles ensure it remains a focal point throughout the growing season.

Fast Facts

• Plant Family: Cupressaceae
• Plant Type: Needled evergreen
• Hardiness Zones: USDA Zones 5-8
• Size at Maturity:
  • Height: 30-40 ft
  • Spread: 15-25 ft
• Bloom Time: Non-flowering
• Bloom Description: Non-flowering
• Sun Exposure: Full sun
• Water Needs: Medium
• Maintenance Level: Low

How to Grow

Optimal establishment for your Cryptomeria japonica ‘Spiralis’ occurs when planted in the spring or early autumn. Place this Japanese cedar where it receives full sun exposure; while it tolerates light shade, full sun encourages the best color and densest growth. The most crucial factor for success is soil quality: the plant demands moist, rich, fertile, acidic, and exceptionally well-drained mediums.

Maintain consistent moisture, especially as the plant establishes its root system. Avoid letting the soil dry out, which stresses this evergreen. Fertilization is generally not necessary if the soil is rich, but a balanced slow-release fertilizer in early spring can benefit younger specimens. Pruning is usually minimal, focusing only on removing damaged or crossing branches to maintain the naturally pyramidal shape.

Protecting your Cryptomeria japonica ‘Spiralis’ from harsh, drying winter winds is highly recommended, particularly in the colder reaches of Zone 5. In these areas, ensuring adequate water uptake before the ground freezes can help prevent dehydration browning (bronzing) of the foliage during winter dormancy.

Landscape Uses

The mature size and texture of Cryptomeria japonica ‘Spiralis’ make it an excellent choice for use as a large specimen tree, commanding attention with its unique spiraling foliage. It excels when planted as a vertical accent near home foundations or strategically placed within borders where its evergreen form provides winter structure.

Due to its significant eventual size, this Japanese cedar also functions effectively as a natural screen or privacy hedge, though regular maintenance might be required to keep formal borders tight. Dwarf cultivars derived from the species are often recommended for smaller spaces, such as rock gardens, but the standard ‘Spiralis’ requires thoughtful placement.

Consider pairing this conifer with broadleaf evergreens or deciduous shrubs that offer contrasting foliage texture—perhaps large-leaved hostas near the base or lighter green foliage masses to highlight the dark, twisted needles of the Cryptomeria japonica ‘Spiralis’.

Standout Features

Noteworthy Characteristics

The genus Cryptomeria is distinct, being unrelated to true cedars. The species, Cryptomeria japonica, is native to Japan, where it is the national tree. Sharply-pointed, awl-shaped, fragrant, green to blue-green needles are spirally arranged along the stems. The ‘Spiralis’ cultivar is known for its slow growth early on, maturing over decades into a striking tree where needles twist tightly around the branches, earning it the common name granny’s ringlets.

Tolerances

• Deer

Potential Problems

This plant generally remains free from serious pest or disease issues, benefiting from its low maintenance rating. Gardeners should monitor for fungal issues like leaf blight or leaf spot, which generally develop when air circulation is poor or humidity remains constantly high, especially if the cultural requirements for well-drained soil are overlooked. Proper site selection, emphasizing good air flow and avoiding waterlogged conditions, is the best preventative measure.

Frequently Asked Questions

What hardiness zones is Japanese cedar suitable for?

The Cryptomeria japonica ‘Spiralis’ is reliably hardy in USDA Zones 5 through 8.

How large does Cryptomeria japonica ‘Japanese cedar’ grow?

This cultivar typically reaches a height between 30 and 40 feet tall, spreading between 15 and 25 feet wide at maturity.

What sun exposure does Cryptomeria japonica ‘Spiralis’ need?

This evergreen performs best when planted in full sun, though it can tolerate locations that receive light afternoon shade.

When does Japanese cedar bloom?

Cryptomeria japonica ‘Spiralis’ is non-flowering; it is grown strictly for its evergreen foliage and unique architectural form.

Conclusion

The remarkable, spirally twisted needles ensure that Cryptomeria japonica ‘Spiralis’ offers exceptional year-round visual interest, making it a standout choice for specimen planting. This low-maintenance Japanese cedar thrives when provided with rich, acidic, moist soil and protection from drying winds. Before adding this beauty to your garden, confirm your location falls within USDA Hardiness Zones 5-8 and prepare the site with excellent drainage.

Companion Planting

When designing a planting scheme around your Cryptomeria japonica ‘Spiralis’, select companions that appreciate similar acidic soil conditions and medium moisture levels. Consider broadleaf evergreens like Rhododendrons or Azaleas, which share similar preferences and offer contrasting forms when planted near the upright structure of the Japanese cedar. Ground covers that provide bright color throughout the summer, such as Hosta varieties with chartreuse or blue foliage, contrast beautifully with the deep green to bronze hues of the conifer.

Design Ideas

Utilizing large conifers like Cryptomeria japonica ‘Spiralis’ in modern landscape design rests on leveraging their unique texture. Place one specimen near a contemporary home exterior to soften hard lines, utilizing its singular, sculptural presence as a focal point. In traditional designs, use it to anchor the corner of foundation plantings where its height can gradually transition to shorter shrubs in the foreground. Its ability to hold winter color also makes it valuable in spots visible from interior windows during the dormant season.