Japanese black pine trees are frequently selected for bonsai by both new or seasoned enthusiasts. These trees respond well to training and develop into a remarkable mature bonsais after years of regular maintenance. Japanese black pines are tough trees that grow fast, which means they require proper consistent care to maintain a bonsai trim. Japanese black pines need optimal growing conditions and appropriate pruning and wiring schedules.
Use a well-drained soil mixture of half akadama and half pumice. Use more pumice for young Japanese black pine trees and more akadama for older bonsai trees.
Supply water to the bonsai with a pH level ranging from 5.5 to 6.5 for ultimate growth. Drench the soil at least twice to ensure even distribution of the water. Water the Japanese black pine as needed to maintain moist soil conditions, but do not make the soil damp.
Provide full sunlight to the Japanese black pine all day, unless temperatures reach more than 100 degrees Fahrenheit regularly. Move the tree to shade at the hottest point of the afternoon during these peak temperatures. Cover the soil in the container holding the bonsai with a cloth to prevent the sunlight from heating the roots of the tree.
Apply organic fertilizer in the middle of spring and the beginning of fall. This type of tree (pine) does not require the same fertilization that other deciduous trees call for.
Prune the Japanese black pine in the end of fall or during winter to minimize sap bleeding. Trim down new branch cuttings with a knife or chisel and apply cut paste. Place newly pruned trees in shady areas for two to four weeks after pruning.
Wire the Japanese black pine at the end of the winter season. Wiring at different seasons could result in sap seepage and branch damage. Do not wire a weak or stressed tree and never expose a wired tree to freezing conditions.