Johnson Grass

  • Johnson Grass is an upright perennial grass, reproducing by rhizomes and seeds.
  • It is well adapted to compete with crop plants.
  • Stems reach up to 6 to 8 feet high or more, from a freely branching fiberous root system, which produces extensive rhizomes within six weeks of germination.
  • The leaves alternate, simple, relatively wide and long.
  • Spikelets are 1-flowered, in groups of 3, in large open panicles.
  • The fruit is a caryopsis or grain, finely striate, reddish-brown with two knobbed rachillae extending upward from the base of the seed.
  • Flowers from May until frost and seeds to frost.

Information referenced from "Johnson Grass" published by the Kansas State Board of Agriculture Plant Health Division.