Japanese White Pine - Pinus
General information: Japanese White Pine creates a striking landscape element
wherever it is used. Often seen as a dense, conical form when young,
Japanese White Pine develops into a 25 to 50-foot-tall, graceful,
irregularly-shaped tree, with an equal or greater spread, and a broad,
flattened canopy. The 1 to 2.5-inch-long needles are stiff and twisted,
forming blue/green tufts of foliage at branch tips, and creating an
overall fine texture to the tree's silhouette. The brownish-red cones are
one to four inches long and persist on the tree for six to seven years.
The needles grow in groups of five, so this tree is also known as
"five-needle pine", especially the cultivar P.
Temperature: Northern climates
Watering: As with other
pines, good drainage is essential.
Feeding: Once a month from early to late spring
and from end of summer to late autumn with a slow-acting organic
fertilizer, and applying chelated iron 2-3 times per year.
If you prefer to use chemical fertilizers, feed every
other week during the same times with a half-strength solution of a
fertilizer for acid-loving plants, such as Miracid. You may wish to
alternate with a balanced fertilizer.
Pruning and wiring The root system should be pruned gradually in the coarse of
repotting, so as to always leave a strong root system. Branch pruning and
wiring should be done in late autumn, and the wire left on the tree for
6-8 months at most. Pinch new shoots in spring to 1/3 of their
Every 1-2 years it is possible to remove all of the
new shoots in late spring, if the tree is healthy and well-fed. This will
result in buds forming in the fall at the sites where the shoots were
removed. The reason this might be done is to form very short internodes on
Repot every 2 or 3 years for young trees (up to 10 years) or every 3 to 5
years for older trees. Repotting can be done in spring before the candles
open or in late summer or early autumn, after the heat of summer has
passed. These are the two periods of greatest root growth in
Because of the rugged quality of the five-needle pine,
a strong rectangular pot should be used. Pines need a deep root system,
and five-needle pines especially need a deep pot to avoid uprooting by
wind, due to their dense foliage. Simon and Schuster's recommends 50%
soil, 10% peat, and 40% coarse sand. Rémy Samson recommends 1 part leaf
mould, 1 part loam, and 1 part coarse sand. Peter Chan recommends 3 parts
coarse sand, 1 part peat, and 1 part loam.
Pines and other conifers grow in association with a
symbiotic fungus which grows in the root ball of the tree. If this fungus
is not present, the tree may die. For this reason, pines and other
conifers should never be bare-rooted, unless steps are taken to
re-introduce the fungus to the repotted plant, such as making a slurry
(thin mud) of the old soil and pouring it over the newly potted
Some experts feel that it is more important to be sure
that the tree always has a healthy root system with sufficient feeder
roots than to worry about symbiotic fungi. They feel that trees are more
likely to die from having their root systems reduced too much at once than
from not having the fungus present. Certainly it is good advice in any
case to be sure the tree has sufficient roots.
Pests and diseases:
Aphids, mealy bug & red spider mites, to name a few.
Return to:Bonsai Info Index