Japanese Cedar Cryptomeria japonica 'Spiralis'

Water

The Japanese Cedar should be watered deeply and thoroughly, allowing the soil to dry out slightly between waterings to encourage healthy root growth. In general, providing about 1.5 to 2 gallons per week should be adequate, but this amount can vary based on weather conditions and soil type. During the growing season in spring and summer, you may need to water the tree more frequently, especially if there are extended periods of hot, dry weather. In contrast, reduce watering in the fall and winter when the tree's growth slows down. It's important not to overwater as this can lead to root rot.

Light

The Japanese Cedar thrives in full sun to partial shade, so it's best to plant it in a spot where it will receive at least four hours of direct sunlight daily. However, in particularly hot climates, some afternoon shade can be beneficial to prevent scorching. The plant's unique spiraled foliage displays best when it receives ample light. Avoid deep shade as it can lead to sparse growth and a less dense habit.

Temperature

The Japanese Cedar is hardy and can withstand a range of temperatures; however, it thrives in temperatures between 60 to 80 degrees Fahrenheit. It can survive minimum temperatures down to about -20 degrees Fahrenheit, but it may need protection from harsh winter winds. The ideal temperature range for this plant is moderate, ensuring that its foliage remains healthy and vibrant throughout the seasons.

Pruning

The Japanese Cedar typically does not require regular pruning due to its natural growth habit, but it may benefit from occasional shaping or removal of dead and damaged branches. The best time to prune is in late winter or early spring before new growth starts. Pruning too often or too late in the season can inhibit the development of its distinctive spiral foliage.

Cleaning

Not needed

Soil

The Japanese Cedar 'Spiralis' prefers a well-draining soil mix, rich in organic matter, with a pH ranging from slightly acidic to neutral (pH 5.0-7.0). A blend of two parts loam, one part peat moss, and one part sharp sand or perlite is ideal for ensuring good drainage and aeration.

Repotting

Japanese Cedar 'Spiralis' should be repotted every 2-3 years, when its growth begins to slow down due to root crowding. Younger plants may require more frequent repotting, whereas mature specimens can be repotted less often.

Humidity & Misting

Japanese Cedar 'Spiralis' does well in moderate to high humidity levels. It thrives when the humidity is around 50-70% which is typical of an outdoor environment in its native habitat or in a temperate greenhouse.

Suitable locations

• Indoor

  Place in bright light, avoid direct sun, ensure ample space.

• Outdoor

  Full sun to partial shade, shelter from harsh winds.

• Hardiness zone

  5-8 USDA

Life cycle

The life of Cryptomeria japonica 'Spiralis', commonly known as Japanese cedar 'Spiralis', begins with seed germination, typically in moist, well-drained soil under partial shade to full sun. After germination, the seedling stage involves the establishment of roots and initial shoot growth. As the plant matures into the sapling stage, it develops its characteristic spirally arranged foliage, with the bark and branches thickening over time. The Japanese cedar 'Spiralis' reaches reproductive maturity after several years, producing male and female cones on the same tree; male cones release pollen while female cones develop seeds. The mature tree stage can last for many years, with the tree continuing to grow in height and diameter while maintaining its health through proper care and environmental conditions. The plant eventually enters the senescence stage, where growth slows and the tree may become more susceptible to diseases or environmental stress before ultimately dying.

Propogation

• Propogation time

  Early spring

• The Japanese cedar, more specifically Cryptomeria japonica 'Spiralis', is commonly propagated through the use of semi-hardwood cuttings. This method involves taking cuttings from the semi-hardwood portion of the plant, which is the current year's growth that has started to mature and toughen up but hasn't yet become fully hardened, typically in late summer or early fall. The cuttings, usually around 4 to 6 inches (10 to 15 centimeters) in length, should include at least one or two sets of leaves. They need to be treated with a rooting hormone before being planted in a well-draining soil mix, kept moist and under a controlled environment, with the use of mist systems or plastic coverings to maintain high humidity. Successful rooting can take several weeks, after which the rooted cuttings can be gradually acclimatized to less humid conditions before being transplanted to their final location.