Mulberry trees (Morus spp.) are fast-growing, berry-producing trees. The red mulberry (Morus rubra) is native to North America and is somewhat rare. The white mulberry (Morus alba) is native to China and is best known for being the primary source of food for the prized silkworm. Both trees have distinctive leaves.
Red and White Mulberry Leaves
Both types of mulberry trees are unusual because their leaves have different shapes. The leaves may be heavily lobed, shaped like a mitten with one small lobe or without any lobes at all. In fact, it is not uncommon for a single branch to hold all three leaf shapes. Although a red or white mulberry tree usually contains leaves of all three shapes, the tree's crown features more leaves without lobes, whereas new shoots have lobed leaves. In general, the younger the tree, the more lobed leaves it has. In autumn, both red and white mulberry tree leaves turn yellow. The leaves of each tree differ in other ways, however.
Red Mulberry Leaves
Red mulberry leaves average 4 to 10 inches in length. The leaves are a dull, dark green and have a rough surface. Underneath, they are covered with fine hairs.The margins have small, sharp serrations. The veins are thin, numerous and obvious. The base of each leaf has a heart shape, and if you split the leaf stem, you will see milky sap.
White Mulberry Leaves
While mulberry leaves are smaller than red mulberry leaves. They average 3 to 4 inches in length. The leaves are bright green and shiny on the surface and lighter green underneath. White mulberry leaves have raised, prominent veins on their underside. The veins branch in three paths from the base of the leaves. The margins of white mulberry leaves are wavy and larger than the serrated edges of red mulberry leaves.
The white mulberry is hardy in U.S. Department of Agriculture (USDA) plant hardiness zones 3b through 9. It grows best well in full sun and adapts to almost any kind of soil, although it prefers well-draining, loamy soil. This adaptable tree can withstand pollution and drought, but it has weak wood that may break in strong wind or freezing conditions. The white mulberry is an aggressive grower. It is found throughout the East and is sometimes called the common mulberry. It is so aggressive, in fact, that it is considered to be invasive in some areas of the country.
Red mulberries, on the other hand, is not common and not considered invasive. The red mulberry is hardy in USDA zone 4 through 8. It thrives as an understory tree in moist, fertile soil and plenty of shade or in full sun. The more shade the tree has, however, the longer its leaves grow. It is often found deep in deciduous forests, along wet slopes.