Mulberries (Morus spp.) decorate landscapes in U.S. Department of Agriculture plant hardiness zones 5 through 10; some gardeners in zone 4 may also have luck. In addition to being attractive trees, mulberries also provide abundant fruit when in the right location. The fruit is sweet and juicy, and it can be used for jellies, wines, juice and as fresh fruit. Unfortunately, the sweet fruit of these trees is also favored by birds and mammals, and it produces unsightly dark stains wherever it lands.
Three Common Species
The three common species of mulberry throughout the United States are white (Morus alba), which grows in USDA zones 4 through 8; red (Morus rubra), a native species that also grows in zones 4 through 8; and black (Morus nigra), which grows in USDA zones 5 through 9. All three have similar characteristics, which may make them difficult to distinguish.
Black and white mulberries are not native to North America; however, these two species have naturalized over the course of hundreds of years, and white mulberry is considered invasive in certain areas. The white mulberry was brought over from China because of its importance to silkworm cultivation. Black mulberries are also native to Asia.
Each of these species reach between 30 and 50 feet tall; some older specimens may reach greater heights. The red mulberry most often grows as an under-story tree beneath the canopy of other forest trees, which often limits its height potential.
Not all leaves on a single tree look alike; mulberry trees come in a handful of shapes. For white and red mulberry, for example, a single tree may have leaves with no lobes, mitten-shaped leaves -- those with one lobe -- or leaves with multiple lobes. The tops of the leaves most often have a distinctive point; the lobes are almost always serrated and rounded.
The leaves of red mulberry tend to be dull and darkly colored; white mulberries, on the other hand, tend to produce shiny or glossy, bright green leaves. Black mulberry leaves resemble those of red mulberry.
The bark of mulberry trees is deeply rigid and often exposes the inner bark. White mulberry's bark is more deeply ridged and browner than the flattened, grayish-colored bark of red mulberry.
White mulberry fruits typically ripen to a whitish or pinkish color, but darker fruits aren't uncommon. Red mulberry fruits are a dark, reddish-purple color and larger than white mulberry fruits. The fruit of the black mulberry is considered by some, including California Rare Fruit Growers, Inc., to be the best-tasting of the three.