The Cryptomeria japonica or more commonly known as the Black Dragon, Japanese Cryptomeria or Japanese cedar is an evergreen tree. This native tree from China and Japan has a moderate growth rate. According to the U.S. Department of Agriculture, the Cryptomeria japonica is hardy in zones 6 through 9, although it can grow in zone 5 if winter protection is provided.
The Cryptomeria japonica is an easy tree to grow for the home gardener. The height of this tree varies on the variety chosen. Some grow 50 to 60 feet tall with a spread of 25 to 30 feet, while others stay short at 3 feet. You can often find this tree growing as a landscape tree, but it does equally well planted in groupings or used for a privacy screen. Some of the smaller varieties are grown in containers for decoration. Some people use them as focal point alongside pools. The male and female flowers are small and the cones are dark brown, averaging 0.5 to 1 inch in diameter.
Plant this tree in a location that receives sun to light shade. Although the Cryptomeria japonica grows in a number of soils, it does best in rich well-drained soil, but that is rich. In the summer, the foliage is a bright blue-green, but in the winter, it takes on a bronze tone. The more wind exposure that this tree receives, the more bronze the color.
Cryptomeria japonica likes an evenly moist soil, but not soggy. If the soil is kept wet all the time, the tree may rot. To check for moisture, insert your finger into the soil to the second knuckle. If the soil is dry, it needs water.
Fertilize
In the spring before your Cryptomeria japonica starts growing, feed it with an acidic fertilizer. Always mix and apply according to the label directions or you risk burning your tree.
Pruning
Early in the summer, examine the tree for dead or diseased branches. When the Cryptomeria japonica is growing in a pot or container, prune them back by a third. This keeps them the right size for container growing. This tree can grow to heights of 50 to 60 feet.
Pests
Inspect the tree for leaf blight. An indication of this disease is if the foliage is turning brown and it is not from wind damage. If your tree has this problem, spray it with a fungicide made to prevent and control leaf blight and leaf spot.
Cryptomeria japonica is subjective to spider mites. If you notice spider mites, simply spray the tree with an insecticidal soap.
