Red Mulberry (Morus rubra) and White Mulberry (Morus alba) are treated here together, since their features are so similar, except for their differences in ripe fruit color in early summer. Red Mulberry, a species native to the entire Eastern United States, is taller and more open and gangly than its counterpart, achieving a height of 60 feet and a spread of 50 feet when found in the open.
White Mulberry, a species native to China, has been planted (and escaped) in both Europe and North America, and is more refined and dense in its branching, becoming 40 feet tall and 40 feet wide under optimum conditions. Both produce abundant amounts of fruits on their female trees, which serve as a source of food for wildlife in early summer, and which serve as the mechanism for their wide dispersal into neglected areas as a "woody weed".
As members of the Mulberry Family, they are also related to other species of Mulberry, and to Osage Orange (which, like the Mulberries, also has heavy wood with white sticky sap, a thin layer of sapwood, and heartwood that is bright yellow).
Planting Requirements - The mulberries are quite adaptable to many different types of soils (rich, poor, deep, thin, rocky, clay, or sandy) and soil pHs (acidic, neutral, or alkaline), preferring moist or dry conditions (but tolerating wet soils for short periods of time) in full sun, partial sun, or partial shade. They are also pollution tolerant, including salt deposition and salt spray. Red Mulberry is hardy from zones 5 to 9, and White Mulberry from zones 5 to 8.
Potential Problems - A host of diseases and pests can affect the leaves, twigs, and bark of the Mulberries, but none seem to slow them down, as these trees have a rapid growth rate with vigor. Witches' broom (top photo) afflicts Mulberry (again, without harm), but is not as commonly seen as in Hackberry.