Plum trees (Prunus domestica, Prunus salicina, and related species) are stone fruit trees in the Rosaceae family, cultivated for their sweet, juicy drupes. Plums are among the most widely adapted of the tree fruits, with species suitable for climates ranging from the cold northern plains to the warm southern states. The two primary domesticated groups are the European plum (Prunus domestica) and the Japanese plum (Prunus salicina).
European plums are native to the Caucasus region and were domesticated in ancient times, spreading through Europe with Roman civilization. The damson and greengage are ancient European types that have been grown for centuries. European plums were brought to North America by early colonists and are well adapted to the northern United States.
Japanese plums are native to China and were developed into modern commercial varieties in Japan. These plums were introduced to the United States in the late 19th century by plant breeder Luther Burbank, who imported and hybridized Japanese plum stock. Japanese plums are better adapted to the warmer regions of the United States.
European plum trees grow 15 to 20 feet (4.5 to 6 meters) tall and are generally self-fertile. The fruit is round to oval with yellow, blue, or purple skin and yellow to green flesh. European plums are used fresh, dried as prunes, and canned. Japanese plum trees are similar in size but more vigorous and require cross-pollination. The fruit is larger and juicier with red, yellow, or black skin and red or yellow flesh.
Plum trees require 800 to 1,200 chill hours depending on the variety. They bloom in early to mid-spring and are susceptible to frost damage. Plums are productive, with a mature tree yielding 50 to 100 pounds (23 to 45 kilograms) of fruit. The trees are relatively short-lived for fruit trees, with productive lifespans of 15 to 20 years.
Plum trees are grown for fresh eating, drying (prunes), canning, and processing into jams, jellies, and baked goods. European plums with high sugar content are dried into prunes, a staple preserved fruit that stores well without special equipment. Japanese plums are primarily eaten fresh.
Plum trees are susceptible to several pests and diseases, including plum curculio, black knot, and brown rot. Regular spraying or integrated pest management is required for reliable production in many areas.