Austrian pine is medium to fast-growing, reaching 40 to 60 feet in the landscape, taller on very old specimens. Combined with the dark green needles, the dense habit makes for an outstanding specimen tree. The pyramidal crown which becomes flat topped and somewhat irregular on older specimens is comprised of thick horizontal branches sweeping horizontally and up as they spread from the trunk. Lower branches are held on the trunk making this a nice, short-trunked specimen or screen plant. Plant it so the lower branches can be left on the trunk to show the true beauty of this pine. Dark furrowed bark is very attractive, particularly on older trees.
Scientific name: Pinus nigra
Pronunciation: PIE-nus NYE-gruh
Common name(s): Austrian pine, black pine
USDA hardiness zones: 5A through 8A (Fig. 2)
Origin: not native to North America
Invasive potential: little invasive potential
Uses: specimen; screen; urban tolerant; bonsai; highway median
Availability: not native to North America
Height: 40 to 60 feet
Spread: 25 to 35 feet
Crown uniformity: symmetrical
Crown shape: pyramidal, oval
Crown density: moderate
Growth rate: moderate
Leaf arrangement: spiral (Fig. 3)
Leaf type: simple
Leaf margin: entire
Leaf shape: needle-like (filiform)
Leaf venation: parallel
Leaf type and persistence: fragrant, evergreen, needled evergreen
Leaf blade length: 2 to 4 inches, 4 to 8 inches
Leaf color: green
Fall color: no color change
Fall characteristic: not showy
Flower color: yellow
Flower characteristics: not showy
Fruit shape: oval, cone
Fruit length: 1 to 3 inches
Fruit covering: dry or hard
Fruit color: brown
Fruit characteristics: does not attract wildlife; showy; fruit/leaves a litter problem
Trunk and Branches
Trunk/bark/branches: branches droop; not showy; typically one trunk; thorns
Pruning requirement: little required
Current year twig color: brown
Current year twig thickness: thick, very thick
Wood specific gravity: unknown
Light requirement: full sun
Soil tolerances: clay; sand; loam; slightly alkaline; acidic; well-drained
Drought tolerance: high
Aerosol salt tolerance: high
Roots: not a problem
Winter interest: no
Outstanding tree: no
Ozone sensitivity: tolerant
Verticillium wilt susceptibility: resistant
Pest resistance: sensitive to pests/diseases
Use and Management
It will stand dryness and exposure, is well adapted to urban conditions including alkaline and clay soil and tolerates road and seaside salt well. Some members of the population may not be adapted to alkaline soil. Unfortunately, Austrian pine is very susceptible to tip blight in the east and for this reason should be used sparingly. There are also some recent reports of pine wilt nematode infesting trees and killing them in one season. But it is one of the best pines for Texas and is highly recommended there. Austrian pine is difficult to transplant so should be planted from containers or moved balled and burlapped after being root pruned.
Propagation is by seed.
There are few cultivars: 'Austriaca'—stout, broadly ovate; 'Pyramidalis'—pyramidal.
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 inside 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 July 15.
Pine wilt nematode can be a serious problem. Infested trees can die in one growing season. There is no control at this time.
Diplodia tip blight is common on Austrian pine and disfigures trees as they reach 25 to 30 years of age. The new growth turns brown and the branch is stunted. Black fruiting bodies may be found on needle bases within the sheath. Fungicides are sometimes suggested to control the disease but as yet no satisfactory control measures have been developed.
Needle blight infects Austrian pine. Dark, slightly swollen bands form on one year old needles in late summer. The part of the needles beyond the band dies. Severely infected trees look thin.