Pinus thunbergii (Japanese Black Pine)


Michael's Opinion

This evergreen is an excellent plant and is a popular choice for road and boulevard plantings due to its salt tolerance. It has a very nice look due to its nicely irregular form. Although it is a desirable plant, cultivars are much more preferred.

Botanical Information

FamilyPinaceae
GenusPinus
Speciesthunbergii
CategoryWoody
TypeTree (evergreen)
OriginNative to Eastern Asia (Japan) introduced in 1855.
Pronunciation

Details

USDA Hardiness Zone5 - 8
USDA Hardiness Ref.
Canadian Hardiness Zone4a - 7a
Canada Hardiness Ref.
RHS Hardiness ZoneH5 - H7
RHS Hardiness Ref.
Temperature (°C)-29 - (-9)
Temperature (°F)-20 - 15
Height8 - 16 m
Spread6 - 12 m
GrowthMedium
Flowering PeriodApril

Description and Growing Information

General DescriptionPopular tree where salt is a problem; it can tolerate all kinds of soil and weather conditions but thrives best in full sun and grows vigorously in well drained clay, sand or loam soils. Tolerant of a wide range of pH conditions.
ID CharacteristicPlants have alternate, spiral, dark green needles with a grey trunk colour. With age Pinus thunbergii will spread and lower its branches in a pendulous way. The trunk is not usually straight but will sweep in a gentle curve.
ShapeThis plant is an excellent irregularly shaped tree and is one of the smaller species of Pines.
LandscapeThis tree is very salt tolerant and is invaluable for seashore plantings and useful to stabilize sand dunes. The trees can also be a very nice specimen/accent plant and can be trained into a bonsai.
PropagationSeeds can be sown in sandy soils in early April, they should be soaked in colder water for about two days to speed up germination.
CultivationTransplants easily if it is balled and burlapped after root pruning. The tree itself thrives and grows best on moist, fertile, well drained soils. It can tolerate salty environments, likes full sun and is very tolerant to heat and drought.
PestsNone serious, stressed trees can possibly get bark beetles which scatter up and down the bark creating holes that look like shot holes. There are also case’s of Pine leaf miners and Pine needle scales. This tree is very resistant to diplodia tip blight.
Notable SpecimensUniversity of Western Ontario, London, Ontario, Canada.
HabitatCoasts of Japan at 1000 m.
Bark/Stem DescriptionBark is dark grey to purple-grey. It is scaly and longitudinally fissured. In old trees the bark turns a black-grey colour.
Flower/Leaf Bud DescriptionWinter buds are white-grey to silvery colour and are not resinous. They are 1.5-2 cm long and are ovoid with a pointed tip.
Leaf DescriptionNeedles are densely crowded and twisted. They are 6-11.5 cm long and are about 8 mm wide. They are stiff and fine-pointed with margins finely toothed.
Flower DescriptionFlowers on this plant are monoecious which means that individual flowers are either male or female and can both be found on the plant. Flowers are yellow and orange and are 3-5 cm long. They are borne in clusters and flower in April.
Fruit DescriptionCones are short and conic-ovoid. They are 4-7 cm long with a brown-grey colour. Cones open late winter; they can be in single or paired. Cones don’t attract wildlife and can cause littering issues when on the ground.
Colour DescriptionNeedle colour is a very nice green. In the autumn needles may turn to a light brown colour. Bark has a grey-purple colour and does not change through the winter season. Current year’s branch colour is brown and turns into a grey colour.
Texture DescriptionMedium textured; irregular shape in the landscape and sometimes with a swerved trunk.

Photographs