Understanding and Classifying Mulberry Trees

Bright red mulberries among healthy green leaves
ikon/Pixabay/Public Domain

Red mulberry or Morus rubra is native and widespread in the eastern U.S. It is a rapid-growing tree of valleys, flood plains, and moist, low hillsides. This species attains its largest size in the Ohio River Valley and reaches its highest elevation (600 meters or 2,000 feet) in the southern Appalachian foothills. The wood is of little commercial importance. The tree's value is derived from its abundant fruits, which are eaten by people, birds, and small mammals. The white mulberry, Morus alba, is native to China and has several differences including size, foliage, and color of fruit.

Fast Facts: Red Mulberry

  • Scientific name: Morus rubra
  • Pronunciation: MOE-russ RUBE-ruh
  • Family: Moraceae
  • USDA hardiness zones: 3a through 9
  • Origin: Native to North America
  • Uses: Bonsai; shade tree; specimen; no proven urban tolerance
  • Availability: Somewhat available, may have to go out of the region to find the tree

Native Range

Red mulberry extends from Massachusetts and southern Vermont west through the southern half of New York to extreme southern Ontario, southern Michigan, central Wisconsin and southeastern Minnesota; south to Iowa, southeastern Nebraska, central Kansas, western Oklahoma and central Texas; and east to southern Florida. It is also found in Bermuda.

Description

  • Size: 60 feet tall; 50 foot spread
  • Branches: Dense branches that droop as the tree grows, and will require pruning for clearance; should be trained to a single leader.
  • Leaf: Alternate, simple, broadly ovate to roughly orbicular, pointed, 3 to 5 inches long, serrate margin, even base, rough and fuzzy undersides
  • Trunk and Bark: Showy trunk; Gray colors with flattened and scaly ridges.
  • Flower and Buds: Small and inconspicuous flowers with off-center buds; usually dioecious but can be monoecious (both male and female flowers on different branches); male and female flowers are stalked axillary pendulous catkins and appear in April and May
  • Fruit: Reddish black and resembling blackberries; reach full development from June to August; composed of many small drupelets developed from separate female flowers ripening together
  • Breakage: Susceptible to breakage either at the crotch due to poor collar formation, or the wood itself is weak and tends to break.

Special Uses

Red mulberry is noted for its large, sweet fruits. A favored food of most birds and a number of small mammals including opossum, raccoon, fox squirrels, and gray squirrels the fruits also are used in jellies, jams, pies, and drinks. Red mulberry is used locally for fence posts because the heartwood is relatively durable. Other uses of the wood include farm implements, cooperage, furniture, interior finish, and caskets.

In landscape use. the species is considered invasive and fruits cause a mess on walks and driveways. For this reason, only fruitless cultivars are recommended.

Differentiating White Mulberry

When compared to red mulberry, the white mulberry has several key differences:

  • Size: Smaller, at 40 feet tall and 40 foot spread
  • Branches: Less dense with fewer branches
  • Leaf: Brighter green, smoother, and more rounded with uneven bases
  • Trunk and Bark: Brown with thick and braiding ridges
  • Flower and Buds: Centered buds
  • Fruit: Less sweet, smaller, and lighter in color, with creamy brownish white berries that start as green, purple, or even black; only females bear fruit

Red and White Mulberry Hybrids

Red mulberry hybridizes frequently with white mulberry, which has become naturalized and somewhat more common than its native sister throughout parts of the Eastern United States.