Introduction

Japanese red pine reaches a height and spread of 30 to 50 feet in the landscape, growing much taller in the woods. Needles are arranged in pairs and remain on the tree for about three years. The needles on this cultivar have a light-yellow color and they have been described by some people as off-color. A distinguishing feature of this tree is the often crooked or sweeping trunk which shows reddish-orange peeling bark. Because lower branches are held nearly horizontal on the trunk forming a picturesque silhouette in the landscape, it is used best as a specimen, not as a mass planting. Needles may turn yellowish during winter on some soils.

General Information

Scientific name: Pinus densiflora

Pronunciation: PIE-nus den-sih-FLOR-uh

Common name(s): 'Aurea' Japanese red pine

Family: Pinaceae

USDA hardiness zones: 3A through 7B (Figure 2)

Origin: not native to North America

Invasive potential: not assessed/incomplete assessment

Uses: Bonsai; specimen

Description

Height: 30 to 50 feet

Spread: 35 to 50 feet

Crown uniformity: irregular

Crown shape: oval

Crown density: moderate

Growth rate: moderate

Texture: fine

Foliage

Leaf arrangement: alternate

Leaf type: simple

Leaf margin: entire

Leaf shape: needle-like (filiform)

Leaf venation: parallel

Leaf type and persistence: needled evergreen, evergreen, fragrant

Leaf blade length: 2 to 4 inches, 4 to 8 inches

Leaf color: yellow

Fall color: no color change

Fall characteristic: not showy

Flower

Flower color: yellow

Flower characteristics: not showy

Fruit

Fruit shape: oval, cone

Fruit length: 1 to 3 inches

Fruit covering: dry or hard

Fruit color: tan

Fruit characteristics: does not attract wildlife; not showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches don't droop; showy; typically multi-trunked; thorns

Pruning requirement: needed for strong structure

Breakage: susceptible to breakage

Current year twig color: green

Current year twig thickness: medium

Wood specific gravity: unknown

Culture

Light requirement: full sun

Soil tolerances: clay; sand; loam; acidic; well-drained

Drought tolerance: moderate

Aerosol salt tolerance: low

Other

Roots: not a problem

Winter interest: yes

Outstanding tree: yes

Ozone sensitivity: unknown

Verticillium wilt susceptibility: resistant

Pest resistance: resistant to pests/diseases

Use and Management

The tree prefers a site with full sun and a well-drained, slightly acid soil. Clay soil is usually not suitable unless the site is well drained, such as on a slope.

There are a few other cultivars: ‘Alboterminata'—yellowish needle tips; ‘Oculis-draconis'—Dragon's Eye Pine—two yellow lines on needles; ‘Umbraculifera'—Tanyosho Pine—20 feet tall, multi-trunked, and perhaps the most popular cultivar.

Propagation is by seed.

Pests

This tree is usually pest-free, with occasional scale, but the list of potential problems is long.

Some adelgids will appear as white cottony growths on the bark. All types produce honeydew which may support sooty mold. European pine shoot moth causes young shoots to fall over. Infested shoots may exude resin. The insects can be found in the shoots during May. Pesticides are only effective when caterpillars are moving from overwintering sites to new shoots. This occurs in mid to late April or when needle growth is about half-developed.

Bark beetles bore into trunks making small holes scattered up and down the trunk. Stressed trees are more susceptible to attack. The holes look like shotholes. Keep trees healthy.

Sawfly larvae caterpillars are variously colored but generally feed in groups on the needles. Some sawfly larvae will flex or rear back in unison when disturbed. Sawflies can cause rapid defoliation of branches if left unchecked.

Pine needle miner larvae feed on the inside of needles causing them to turn yellow and dry up.

Pine needle scale is a white, elongated scale found on the needles. Pine tortoise scale is brown and found on twigs. Depending on the scale, horticultural oil may control overwintering stages.

Pine spittle bug lives and hides in a foamy mass.

Spruce mites cause damage to older needles and are usually active in the spring and fall. Mites cause older needles to become yellowed or stippled.

Zimmerman pine moth larvae bore into the trunk. The only outward symptoms may be death of parts of the tree or masses of hardened pitch on the branches.

The larvae of pine weevils feed on the sapwood of the leaders. The leader is killed and the shoots replacing it are distorted. First symptoms are pearl white drops of resin on the leaders. The leaders die when the shoot is girdled as adults emerge in August. Prune out and burn infested terminals before mid-July.

Pine wilt nematode can cause considerable damage.

Diseases

They are susceptible to needle blight, rusts. Canker diseases may cause dieback of landscape pines. Keep trees healthy and prune out the infected branches.

Needle cast is common on small trees and plantation or forest trees. Infected needles yellow and fall off.