Walking Shoal Creek in spring has its hazards. The trails can be crowded, a mishmash of bikers, walkers, and runners. Poison ivy is snaking out into the trails. Mulberries are leaving their telltale stains on cars, sidewalks, and the unsuspecting.

There are two types of mulberry along Shoal Creek, red mulberry (Morus rubra) and white mulberry (Morus alba). The white mulberry is from northern China, first introduced in the United States in hopes of supporting a silk industry. The leaves of the white mulberry are the preferred food of the silkworm. The silk industry never took hold, but the white mulberry has now spread throughout the eastern U.S. and in many places hybridizes with the native red mulberry.