Introduction
Soaring to 120 feet in its native habitat, Oriental Spruce is more often seen at 25 to 40 feet in the landscape, growing slowly into a dense pyramidal silhouette which casts dense shade beneath. There are some specimens in landscapes 50 or 60 feet tall but these are rare. The horizontal branches bend downward slightly at the tips, and are generously clothed with short, dark green needles. Both male and female flowers are considered insignificant although the male flowers resemble small red strawberries. The flowers are followed by the production of two to four-inch-long and one-inch-wide, reddish-purple cones which mature to a shiny brown. Unfortunately the tree is rare in the industry.
General Information
Scientific name: Picea orientalis
Pronunciation: PIE-see-uh or-ee-en-TAY-liss
Common name(s): Oriental Spruce
Family: Pinaceae
USDA hardiness zones: 5A through 7B (Fig. 2)
Origin: not native to North America
Invasive potential: little invasive potential
Uses: specimen; screen; Bonsai
Availability: somewhat available, may have to go out of the region to find the tree
Description
Height: 50 to 60 feet
Spread: 15 to 25 feet
Crown uniformity: symmetrical
Crown shape: pyramidal
Crown density: dense
Growth rate: slow
Texture: fine
Foliage
Leaf arrangement: alternate (Fig. 3)
Leaf type: simple
Leaf margin: entire
Leaf shape: needle-like (filiform)
Leaf venation: parallel
Leaf type and persistence: evergreen, needled evergreen
Leaf blade length: less than 2 inches
Leaf color: green
Fall color: no color change
Fall characteristic: not showy
Flower
Flower color: red
Flower characteristics: not showy
Fruit
Fruit shape: oval, elongated, cone
Fruit length: 1 to 3 inches, 3 to 6 inches
Fruit covering: dry or hard
Fruit color: brown
Fruit characteristics: does not attract wildlife; showy; fruit/leaves not a litter problem
Trunk and Branches
Trunk/bark/branches: branches droop; not showy; typically one trunk; thorns
Pruning requirement: little required
Breakage: resistant
Current year twig color: brown
Current year twig thickness: medium, thick
Wood specific gravity: unknown
Culture
Light requirement: full sun, partial sun or partial shade
Soil tolerances: clay; sand; loam; slightly alkaline; acidic; well-drained
Drought tolerance: moderate
Aerosol salt tolerance: unknown
Other
Roots: not a problem
Winter interest: no
Outstanding tree: yes
Ozone sensitivity: unknown
Verticillium wilt susceptibility: resistant
Pest resistance: resistant to pests/diseases
Use and Management
Best used as a specimen in protected landscapes, Oriental Spruce lends a graceful addition to any yard. Leave plenty of room for lateral branch growth near the base of the tree as it looks odd when lower branches are removed. Watch for mite infestations during hot weather.
Oriental Spruce should be grown in full sun or partial shade on well-drained soil, and will tolerate infertile, even rocky soils. However, Oriental Spruce should only be used where winters are not extremely dry, and the plants should be located where they will not be exposed to harsh winter winds or air pollution. Excessively dry, windy, winter weather can brown the foliage. Generous irrigation in the fall will help the tree pull through the winter.
Cultivars include: `Aurea', new growth is yellow, gradually changes to green; `Gowdy', narrow columnar form, small green leaves; `Gracilis', small conical form, 15 to 20 feet tall, bright green needles; `Pendula' (`Weeping Dwarf'), compact, pyramidal weeping form.
Propagation is by seed.
Pests
Mites, aphids and bagworms are the most common pests.
Two gall commonly attack Spruce. Eastern Spruce gall adelgid forms pineapple like galls at the base of twigs. Galls caused by Cooley's Spruce gall adelgid look like miniature cones at the branch tips. The gall adelgids do not kill trees unless the infestation is heavy. A few galls on a large tree are not serious.
Bagworms make a sack by webbing needles together. Small numbers may be picked off by hand or use Bacillus thuringiensis .
Spruce budworm larvae feed on developing buds and young needles. The yellowish brown caterpillars are difficult to see.
The Spruce needle miner makes a small hole in the base of a needle then mines out the center. Dead needles are webbed together and can be found on infested twigs.
Pine needle scale is a white, elongated scale found feeding on the needles only. Populations would have to be quite high to cause major damage.
Spider mites can be problem in summer after hot dry weather. The small insects can't be readily seen with the naked eye. The first noticeable symptoms are yellowing of the oldest needles on infested branches. Close inspection with a magnifying glass will confirm the presence of the mites.
Sawfly larvae may feed on the needles. One infestation will usually not kill the tree.
Diseases
Spruce may be attacked by needle casts. One, caused by Lophodermium piceae , causes needles to turn yellow or brown and drop off. Another, caused by Rhizosphaera kalkhoffi , affects the lowest needles first then moves up the tree. Infected needles are a mottled yellow.
Several rust diseases attack Spruce but these are rarely seen. Infected needles turn yellow and drop off.