Cherry and plum trees are deciduous stone fruit trees, producing a fleshy fruit with a single seed with a hard outer seed coat. Most cultivars of cherry and plum require cross-pollination in order to produce a crop, but there are some varieties of both that are self-pollinating. Cherries and plums are among the cold-hardiest of fruit trees, according to the University of Minnesota, but both require some shelter from cold winds. Beyond that, their differences mount up.
Compare the leaves of cherry and plum trees. Cherry leaves are usually 2 to 3 inches long, and have a narrow, tapered shape with a pointed tip. They also have a fine, sawtooth edge. Plum leaves are slightly larger, with a wider shape and blunt tip. Plum leaves are narrow at their stems, while cherry leaves are narrowest at their tips.
Cherry trees produce clusters of small, red, yellowish red to dark red fruit on long, thin stems, about half-inch to 1 inch in diameter. Plum trees produce short, stout-stemmed, much larger fruit, often 3 to 4 inches in diameter. Plums can be a wide variety of colours, from blue to deep purple to orange red. Do a taste test, too. Cherries can be sweet or tart, depending on the cultivar, while plums have a mellower, uniformly sweet taste. Notice that the pit of a plum is quite a bit larger than the stone of a cherry.
Look at the bark of a cherry tree. You'll find it smooth, reddish brown and almost shiny in appearance, especially on the twig. The smooth surface is interrupted by slightly raised, grey welts. Cherry bark is also thin and easily damaged. Plum bark on the other hand, is shaggier, tougher-textured and grey. Some plum varieties have bark that appears to be peeling, quite like a birch's, and the peeling becomes more pronounced as the tree matures.