How can you get rid of johnson grass permenatly?

Johnson grass is a tough perennial weed problem. It grows from one to six feet high and the leaves are up to an inch or so wide, and they have a distinctive white vein in the center. The seedheads of Johnson grass are purplish and appear from June through October. The brown seeds will germinate in spring. It is not unusual for Johnson grass to sprout from creeping root stocks, so once you get rid of one clump, you may very well see another emerge close by.

The reason that johnson grass is so hard to control is that the root system can reach 3-6 feet deep and new plants will emerge from any root pieces that survive herbicides or digging. In landscape beds, Johnson grass can be controlled using herbicides formulated for grass type weeds, or a total kill herbicide applied carefully. Johnson grass can be controlled in lawns with preemergent herbicides applied in spring, but existing clumps will have to be dug out.

Multiple applications of the herbicides and persistent digging will be needed in order to get rid of Johnson grass.