Johnsongrass

Description

Johnsongrass is not a common weed in turf situations. It is frequently found on roadsides, but is also found in pastures and disturbed fields. It does not grow well in frequent, close mowing situations. As an adult plant, johnsongrass is characterized by its dense growth habit, with stems that can reach 6 feet in height. The leaf blades are rough, and the prominent white raised midveins that run the length of the leaf are distinctive. The seedhead is purple.

Cultural Control

Perennial grass weeds are not desirable as turfgrass species under any conditions. Therefore, every effort should be made to prevent these weedy grasses from becoming established in turf, as selective control measures are usually difficult. Selection of adapted turfgrass species and cultivars and the use of cultural practices are important in minimizing weedy grass encroachment and competition. Management practices include: (1) mowing at the recommended height for the selected turfgrass and removing clippings when seedheads of grassy weeds are present; (2) applying the proper amount of nitrogen at the correct time according to the turfgrass present; and (3) using soil tests to determine needed nutrients and lime.

Species Data

Johnsongrass seedheadFigure 1. Johnsongrass seedhead.Johnsongrass seedheadFigure 2. Johnsongrass seedhead.Johnsongrass seedheadFigure 3. Johnsongrass seedhead.Johnsongrass vernationFigure 4. Johnsongrass vernation.Johnsongrass vernationFigure 5. Johnsongrass vernation.Johnsongrass auricleFigure 6. Johnsongrass auricle.Johnsongrass auricleFigure 7. Johnsongrass auricle.Johnsongrass auricleFigure 8. Johnsongrass auricle.Johnsongrass auricleFigure 9. Johnsongrass auricle.Johnsongrass leaf blade tipFigure 10. Johnsongrass leaf blade tip.Johnsongrass leaf blade widthFigure 11. Johnsongrass leaf blade width.Johnsongrass collar typeFigure 12. Johnsongrass collar type.Johnsongrass collar typeFigure 13. Johnsongrass collar type.Johnsongrass sheath marginFigure 14. Johnsongrass sheath margin.