Japanese black pine

Sun

Full sun; shade produces thin growth and a less compact crown.

Water

Water regularly while establishing; moderately drought-tolerant once rooted. Avoid soil that stays wet.

Soil

Well-drained sandy or loamy soil, preferably acidic to neutral; tolerates poor soil and salt spray but not waterlogging.

Height

30-60 ft (9-18 m), occasionally taller

Spread

20-40 ft (6-12 m)

Foliage

Evergreen. Stiff, pointed, dark green needles, usually 3-5 in (7.5-13 cm) long, carried in pairs; conspicuous silvery-white buds.

Growth

Moderate, often 12-24 in (30-60 cm) a year when young and well established.

Care needed

Medium

• Deer resistant
• Drought tolerant
• Wildlife

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   7 ft (2 m)

2. After 1 year

   8 ft (2.6 m)

3. After 2 years

   10 ft (3.2 m)

4. After 3 years

   12 ft (3.7 m)

5. After 5 years

   16 ft (4.9 m)

About 20 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Invasive in

the US

Growth rate

Moderate

• Water deeply during dry spells for the first two growing seasons, allowing the surface soil to dry between waterings.
• Spread 2-3 in (5-8 cm) of organic mulch over the root area, keeping it clear of the trunk.
• Do not fertilise routinely; feed lightly in spring only if growth is weak and a soil test indicates a deficiency.
• Stake only if the root ball moves in wind, and remove supports after the first growing season.
• Keep lawn equipment away from the trunk and avoid digging or compacting soil over the roots.

Pruning. Remove dead, damaged or crossing branches in late winter during dry weather. For a denser outline, shorten soft new shoots, called candles, in late spring before the needles fully expand; do not cut back into bare old wood or top the tree.

Late winter

Check branch structure and remove dead or damaged wood during dry weather.

Spring

Plant where drainage is good, water thoroughly and mulch without covering the trunk base.

Late spring

Shorten soft candles only if you want to control growth or maintain a trained shape.

Summer

Water young trees during dry spells and check for scale insects, shoot dieback or sudden browning.

Autumn

Expect some older inner needles to yellow and fall; investigate browning that also affects shoot tips.

Winter

Check young trees for wind-rock and loosen ties that rub or constrict the trunk.

• Use as a specimen in an open lawn or gravel garden where its irregular crown has room to develop.
• Plant in a coastal garden as a salt-spray-tolerant structural tree, away from sensitive natural dunes.
• Train as a sculptural focal point in a Japanese garden with rocks, gravel and low planting.
• Contrast its coarse, dark needles with fine grasses and low, rounded shrubs.

Garden styles it suits: Japanese, Zen dry garden, Coastal, Architectural minimal, Dry gravel garden and Winter interest.

Plant it with: Japanese maple, Shore juniper, Japanese forest grass, Mondo grass, Azalea and Bearberry.

Wildlife: Provides evergreen shelter and nesting cover for birds; its seeds are eaten by birds and small mammals. Pollen is wind-dispersed rather than a significant food source for pollinating insects.

• Pine wilt can cause rapid browning and death, especially in hot-summer regions. Seek a prompt diagnosis; infected trees cannot usually be saved and should be removed and disposed of according to local advice.
• Diplodia tip blight causes stunted, brown new shoots, often on stressed trees. Prune affected shoots in dry weather, remove fallen cones and reduce drought stress.
• Pine needle scale appears as small white coverings on needles and can weaken growth. Encourage beneficial insects and, if needed, use a locally approved treatment timed to the crawler stage.
• Poor drainage can cause root decline and sparse, yellowing foliage. Correct drainage before planting; established trees in persistently wet sites may need replacement.

Not known to be toxic to people, cats, dogs or horses. Needles and resin may irritate the mouth or stomach if eaten, and stiff needles can cause physical injury; discourage chewing.

Where it spreads. Can escape cultivation and spread into coastal dunes in the northeastern United States, including Long Island, New York. Avoid planting beside sensitive dune habitats and check local invasive-plant guidance.

• Japanese red pine (Pinus densiflora)

  Has softer, more slender needles and orange-red upper bark; Japanese black pine has stiffer needles, pale buds and darker bark.

• Austrian pine (Pinus nigra)

  Also has stiff needles in pairs, but its buds are generally brown and resinous rather than conspicuously silvery white.

• Japanese white pine (Pinus parviflora)

  Has shorter, often bluish needles in bundles of five rather than the long, dark green pairs of Japanese black pine.

The species name thunbergii honours Swedish botanist Carl Peter Thunberg, while 'black pine' refers to its dark bark.

Propagation. Usually grown from seed sown in spring; a short period of cold, moist stratification can improve germination. Named cultivars are generally propagated by grafting to preserve their characteristics.

Accepted botanical name

Pinus thunbergii

In the US and Canada

Introduced in the lower 48 states.

Sources: GBIF (CC BY 4.0) and USDA PLANTS. The care and design notes are LandscapeGPT's own.