White Mulberry

Morus alba

Invasive Species

Recognized by the combination of alternate, coarsely toothed and often lobed leaves that are lustrous above and white to dark purple, blackberry-like fruit.

The white mulberry was originally brought to North America as early as the 1600s to establish a silkworm industry. As a preferred host plant for feeding silkworm caterpillars, many white mulberries were planted, thrived, and reproduced, though the silkworms did not. While the silk industry never materialized, the legacy of this failure is white mulberry trees scattered across the continent.

An increasing concern is that the white mulberry, which easily hybridizes with the red mulberry, is genetically “swamping” the red mulberry out of existence by constantly interbreeding with it, to the point where there is some concern many of our remaining red mulberries in Pennsylvania have some intermixing of white mulberry genes.