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Invasive, Exotic Plants of the Southeast


Johnson Grass

Johnson Grass

Common Name: Johnson Grass

Scientific Name: Sorghum halepense

Identification: Johnson Grass is a perennial grass reaching 6 feet in height.  Leaves are 2 feet long and alternately arranged along the stout stem.  The purple flowers are arranged on loose 6-inch long panicles.  The seeds are small, occur in sets of 3, and contain single awns.

Ecology: Johnson Grass is extremely invasive and adapted to a wide variety of habitats.  This grass grows in open forests, old fields, ditches, wetlands, and disturbed sites.  It spreads by roots and seeds transported by animals and people.  Few wildlife species use Johnson Grass and it will outcompete native vegetation.

Plant Control:Johnson Grass can be difficult to control. In the home landscape, digging up and bagging the grass clumps can be an option but any broken off tillers (roots) can form new plants. Dense patches can be treated with 5% glyphosate and surfactant solution in late summer. Although there are stronger herbicides available, they may not be appropriate for use in the home landscape.  Monitor and re-treat annually until control is achieved.
Alternative Native Species: Switchgrass (Panicum virgatum), Indiangrass (Sorghastrum nutans), Splitbeard Bluestem (Andropogon ternarius), Little Bluestem (Schizachyrium scoparium)

When using herbicides remember to follow label-recommendations.  Any mention of trade, products, or firm names is for descriptive purposes only and does not imply endorsement by North Carolina State University.

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