Tall and spirelike or dwarf in size and quaint in a rock garden, spruce trees (Picea spp.) are slow-growing conifer trees. They provide windbreaks from cold winter winds and become stately and beautifully shaped specimen trees for cool-summer regions. Avoid cutting boughs or entire spruce trees for use as Christmas decor, since the stems and needles dry out quickly and shatter when touched, unlike those of fir trees.
The botanical name for spruce is Picea, which comes from the Roman word "pix" meaning "pitch" or perhaps from "picis," a name for a pitch pine, according to The Gymnosperm Database. English speakers call it a spruce, but in French-speaking Canada it is called "épinette" and in France, "épicéa." Across Scandinavia spruces are known as "gran" and as "fichte" in Germany. Russians call it "jel," Japanese call it "momi" and in China, "yunshan."
There is some ambiguity among taxonomists as to the precise number of spruce species extant because there has been inadequate study of spruces native to central and eastern Asia. Overall, between 30 to 40 species of spruces grow.
Spruces grow naturally only in the cool forests or higher montane elevations in the northern hemisphere. Thus, they are found only in North America, Asia and parts of Europe. The southernmost-growing spruce species is found in the mountains of Taiwan near the Tropic of Cancer--the Taiwan spruce (Picea morrisonicola). Spruce forests comprise the bulk of habitat across Russia, Scandinavia, Alaska and Canada, but the most diversity of spruces occurs in the southwestern parts of China and in the mountains of Japan.
While there isn't complete data on the ages of spruce trees, the oldest plants tend to be found growing on sites with extreme stresses from drought, cold or low light levels from excessive forest shade. These conditions dominate in high elevations on mountains that occasionally suffer drought. The Gymnosperm Database entry for Engelmann spruce (Picea engelmannii) reveals that the age of 911 years holds the title as the oldest growing spruce species. The title tree, named "FCC 23," grows in central Colorado in the United States.
Spruce trees relish any deep, moist but well-draining soil that is acidic to neutral in pH (7.2 and lower). Serbian spruce (Picea omorika) is one that grows well in alkaline soil (ph above 7.2); it is native to the Drina River valley region in Bosnia and Serbia.