ABSTRACT
Johnson grass is native to the Mediterranean region but is now found in essentially all temperate regions of the world. It was introduced to the United States in the early 1800s as a forage grass, and by the end of the 19th century Johnson grass was growing throughout the United States. In North Carolina, it occurs statewide. Each plant can produce hundreds of seeds with potential for far ranging dispersal by water, wind, livestock, commercial seed contamination, and contaminated machinery, grain, or hay. The immense, rapidly growing rhizome system of Johnson grass gives this plant a competitive edge allowing it to form dense colonies, displacing desirable vegetation, and restricting tree seedling establishment. In addition, the rhizomes regenerate easily from small pieces and are capable of growing or remaining dormant in a wide range of environmental conditions. Johnson grass occurs in temperate, subtropical, and tropical regions where it frequently occurs in ditches, field borders, cultivated lands, waste places, roadsides, other rights-of-ways, creeks, canal banks, and prairies.
