If there is a predominant leader, it is often a thick twisting structure rather than a straight trunk.
The tree has long dark-green needles with contrasting silky white candles with an upright new growth.
Japanese black pine grows best in sandy loam and in a sunny location.
The Spruce / Evgeniya Vlasova
It is also one of the most popular of all pine species forbonsai.
Japanese Black Pine Care
Here are the main care requirements for growing a Japanese black pine.
Light
Japanese black pine should get at least six hours of direct sunlight daily.
The Spruce / Evgeniya Vlasova
Some light afternoon shade is acceptable.
Soil
The soil must be moist but well-drained.
Sandy loam is ideal; Japanese black pine does not tolerate soggy soil and poor drainage.
The Spruce / Evgeniya Vlasova
It prefersacidic soilbut can also grow in slightly alkaline soil.
Temperature and Humidity
This tree generally does well in USDA zones 5 to 8.
Humid conditions may foster fungal diseases, especially if pruning is done during wet periods.
The Spruce / Evgeniya Vlasova
Fertilizer
This tree, like most pines, does not usually require regular feeding.
If your soil is poor in nutrients, add acomplete fertilizerin the spring.
Potted bonsai specimens, however, can benefit from more frequent feeding.
Many popular cultivars are dwarf varieties, some of which remain only 3 to 10 feet tall.
Pruning can also help the trees remain dense and full when they are planted as a screen.
Its ability to handle this kind of pruning makes it a popular tree for bonsai practice.
Harvested seeds from ripened cones are fairly easy to germinate and grow into seedlings.
As with mostbonsai plants, Japanese black pines should be repotted every few years to prune back the roots.
In partial shade, the needles will be lighter than a tree grown in full sun.
Water it regularly but let the soil dry out to the touch between watering.
Pruning stresses the bonsai tree and causes sap bleeding.
Do substantial pruning only between fall and early winter.
Mulching the soil well is also beneficial.
If necessary, small trees can be protected with a tent or screen of burlap for the winter.
These tiny soil worms infect trees through holes bored by bark beetles.
Other possible pests include sawflies, Nantucket tip moths, and bark beetles.
Leaf blight that progresses into canker disease is usually fatal.
Other fungal diseases are also possible, including various rusts and cankers.
Badly affected trees that have developed cankers from Diplodia can’t be cured.
Avoid pruning during wet weather when fungi are easily transmitted.
In addition, avoid fertilizing lawns around pine trees, as excessive nitrogen also fosters fungal diseases.
This issue can easily be rectified by pruning.
Excessive Shedding
This tree is surprisingly messy because it sheds a considerable volume of needles and cones.
This is not unusual for a pine tree butP.
thunbergii’svery dense growth is messier than most pines.
Brown Needles
Cold winter winds can dry out needles and turn them brown.
It has a moderate growth rate, sometimes as much as 1 to 1 1/2 feet per year.
Its fast-growing nature also makes it a good choice for establishing an effective screen within a few years.
The Art of Bonsai.Virginia Tech Extension.
Wisconsin Horticulture Division of Extension.
Pinus Thunbergiana: Japanese Black Pi.
University of Florida Extension.
Pinus thunbergii; Japanese Black Pine.University of Arkansas Division of Agriculture.
