Johnsongrass

August 28, 2015

Sorghum halepense (L.) Pers.

Life cycle

Rhizomatous perennial.

Johnsongrass patch
Patch of Johnsongrass.

Leaves

Bright green leaves are hairless with a prominent, white midvein. Leaves are rolled in the bud and may be up to 24 inches long. Leaf sheaths are also hairless. 

Ligule

Very prominent, jagged, membranous ligule.

Johnsongrass ligule
Johnsongrass collar region.

Stems

Erect, stout, hairless stems may reach 10 feet in height. Round to sometimes flattened stems are purple-tinted at the base. Plants form dense patches by purplish, thick, scaly rhizomes.

Johnsongrass rhizome
Johnsongrass rhizome section.

Flowers and fruit

The seedhead is a purple, very large, open and spreading, pyramid-shaped panicle that consists of numerous whorled branches. Seeds are oval, shiny and reddish brown.

Johnsongrass seedhead
Johnsongrass seedhead.

Reproduction

Seeds and rhizomes.

Print a PDF of this page: Johnsonrass

Back to identifying Christmas tree weeds.

Other Documents in this Series

You Might Also Be Interested In

Accessibility Questions:

For questions about accessibility and/or if you need additional accommodations for a specific document, please send an email to ANR Communications & Marketing at anrcommunications@anr.msu.edu.

Tag List
  • integrated pest management

About

Resources

Events

Michigan State University
  • Spartans Will.
  • © Michigan State University

MSU is an affirmative-action, equal-opportunity employer, committed to achieving excellence through a diverse workforce and inclusive culture that encourages all people to reach their full potential.

Michigan State University Extension programs and materials are open to all without regard to race, color, national origin, gender, gender identity, religion, age, height, weight, disability, political beliefs, sexual orientation, marital status, family status or veteran status. Issued in furtherance of MSU Extension work, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Quentin Tyler, Director, MSU Extension, East Lansing, MI 48824. This information is for educational purposes only. Reference to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned.

The 4-H Name and Emblem have special protections from Congress, protected by code 18 USC 707.

We comply with the Federal Trade Commission 1998 Children’s Online Privacy Protection Act (COPPA).