Plum trees (Prunus spp.) are native to the cool or cold winter regions of the Northern Hemisphere, mainly in Asia, Europe and North America. These fruit trees are closely related to cherries and peaches and even more closely related to apricots, with which plums can hybridize. Plant breeders have hybridized many different plum species to get more desirable fruiting and flowering plum trees for the garden.
There are numerous plum species native across the cold winter parts of the Asian continent, and also have natural ranges that extend into eastern Europe. One of the more popular modern plums, Prunus salicina, is commonly called the Japanese plum, although this species is native to China.
As with Asian plum species, there are numerous other, less popular or commercialized plums native to parts of Europe. The European plum (Prunus domestica) is believed to have originated in far-eastern Europe, in the Caucuses. Arguably, the region near the Caspian Sea is western Asia. The cherry plum (Prunus cerasifera) is native to parts of central and eastern Asia and nearby parts of western Asia. Blackthorn or sloe (Prunus spinosa) is found naturally across much of southern, central and eastern Europe.
Blackthorn (Prunus spinosa) is also native to extreme northwestern Africa. Other plum species native to Europe or western Asia may have natural ranges that extend around the rim of the Mediterranean Sea, including the northern coast of Africa.
Of the seventeen North American plums, perhaps the wild plum, Prunus americana, is the most widely known or encountered in the eastern woodlands. Other species of note include the beach plum (Prunus maritima), Oregon plum (Prunus subcordata), Canadian plum (Prunus nigra) and Mexican plum (Prunus mexicana).
The plum species can be crossed with each other to produce desirable hybrid plants. Whether these hybrids produced high-quality and tasty fruits for eating or are merely ornamentally pleasing in the garden, over 2,000 cultivars, or cultivated varieties, exist today.
Since plums are so closely related to apricots, successful attempts to combine the qualities of the two yield plants called plumcots, apriums, or pluots.