Bring both berries and birds to your garden with a native mulberry tree. There are two species native to North America – the red mulberry (Morus rubra) and the Texas mulberry (Morus microphylla).
The red mulberry is a handsome tree found throughout most of the eastern United States, west to South Dakota, Nebraska, Kansas, and Texas, and is native to a total of 33 states. Unfortunately, this valuable tree is an endangered species in Connecticut and Massachusetts, a threatened species in Michigan and Vermont, and an imperiled species in Ontario. In addition, it is declining in the Midwest.
The Texas mulberry is a small tree or shrub, and is widespread in the southwestern U.S. It is native not only Texas, but also to Arizona, New Mexico, and Oklahoma.
There are also two non-native invasive mulberry species. White mulberry (Morus alba), found throughout the U.S. except for Alaska, Arizona, and Nevada, threatens the survival of our native red mulberry. Paper-mulberry, (Broussonetia papyrifera), occurs in 28 states in the Northeast, Southeast, and Midwest, and is invasive in natural areas. For more information on these two species, see “Additional Notes” below.
Value for Birds
Red mulberry is a sure-fire way to bring every fruit-eating bird in the nearby vicinity to visit your yard. A full 50 species of birds are known to feed on mulberries, and they are a favorite food of over 30 species. These include thrushes, robins, waxwings, vireos, orioles, cardinals, and finches, among others. Although the birds will feed on other mulberries, the berries of the native red mulberry are preferred by them. The fruit-ing period is from June to August, so the berries provide nourishing summer food for fruit-eating birds.
A number of insects also feed on the red mulberry and, in turn, are likely to provide good bird food.
Other Wildlife Values
Many small mammals feed on mulberries, including fox, opossums, raccoons, skunks, squirrels, and native wood rats. Deer browse on the twigs and foliage, while beaver consume the bark.
Insects feeding on red mulberry leaves include several scale insects and the Comstoch mealy bug. Root-knot nematodes sometimes damage the tree’s roots. The larvae of the American plum borer and the mulberry borer attack the twigs and stems. Red mulberry is also the host plant for the caterpillars of the mourning cloak butterfly.
Landscape Notes
Red mulberry is a handsome shade tree, growing to 50 feet. It branches low from a short main trunk with dense branching, creating a beautiful form that is about as wide as it is tall. It prefers moist areas such as floodplains, mesic savannas, and rich woods, but it will tolerate dry areas. Avoid planting the tree near sidewalks, sitting areas, clotheslines, or driveways, since the fallen fruits and bird droppings will be a nuisance.
Texas mulberry is a shorter tree, reaching 25 feet, and similar to the red mulberry, it is as wide as it is tall. It grows along creeks and in canyons, preferring dry, well-drained locations. Its fruits are edible, but sour.
For both species, sexes may occur on separate plants or the same tree may have some branches with male flowers and some with female flowers.
Also of Interest
The red mulberry grows throughout my neighborhood in southeastern Wisconsin, and fruits prolifically. Its berries resemble blackberries, and different trees have berries of various quality – some more delicious than others. Not all the berries on a tree ripen at once, which means I can harvest the berries over a month’s time in early summer. My family and I eat some berries immediately, fresh or in pies. The rest I freeze. Although I harvest many for our uses, there are abundant berries higher on the trees for the birds. (I pick the berries, but some people harvest them by laying a sheet below the tree, and shaking off the ripe berries. This does not work well for me since our trees grow on slopes.) Be forewarned – your hands will be dyed purple – but you’ll find the delicious taste of the mulberries worth the temporary stains.
The American Indians used the red mulberry for food and medicinal uses. In addition, Choctaw Indian women spun thread from the fibrous bark of young mulberry shoots and wove cloaks for themselves.
Additional Notes – Related Invasives
White mulberry is an invasive species which was introduced during colonial times in an unsuccessful attempt to establish a silkworm industry, and it has been spreading ever since. Along with cultivars like the Russian mulberry (Morus alba var. tartarica), it has also been promoted by the horticultural industry. The white mulberry readily hybridizes with red mulberry, and could eventually replace and eliminate it. In addition, it spreads a harmful root disease to the red mulberry. The paper-mulberry, widely planted as an ornamental tree in the Southeast, is invasive in natural areas.
Asian black mulberry has been sighted in three states. And (Morus nigra) has been spotted in three states: Ohio, West Virginia, and Kentucky. It has not yet been noted as an invasive. Morphologically, it is virtually indistinguishable from the native red mulberry (M. rubra).
To eliminate these non-natives, pull or dig out small trees, as I did when I discovered a white mulberry in my yard. Cut and treat the stumps of larger trees with an herbicide. Be sure to make a careful identification before removing the non-natives, since it can be difficult to distinguish between red mulberry and the non-native look-alikes. A careful look at the leaves can be helpful. The red mulberry has evenly hairy undersides on its leaves. The white mulberry’s leaves are hairless below, except for a few hairs on the midvein beneath. The paper-mulberry has densely gray-hairy leaves. The fruits of red mulberry are dark red-to-purple berries, while the fruits of white mulberry may be red or white. The paper-mulberry has reddish purple to orange fruits.