Grassy Weed – Johnsongrass

(Sorghum halepense)

Johnsongrass is a perennial grassy weed capable of growing to considerable heights and reproduces rapidly. Sorghum halepense is commonly found growing along roadsides, in pastures, hay fields, and, most frequently, among cultivated croplands. Johnsongrass thrives throughout much of North America.      

Identifying Johnsongrass -

Johnsongrass can be identified as a coarse, vertically growing perennial grassy weed forming from long, thick and scaly rhizomes that are sharply pointed and more than 1/4" thick. The ligule is very tall and abrupt, with jagged hairs on the top. Its blades are flat and very long, with sparse hairs near the ligule. Johnsongrass also includes a ring of hairs below the nodes at the base.

Johnsongrass also produces a large, noticeable seedhead that often has a purplish tint. 

Johnsongrass Control -

Johnsongrass is frequently a problem in cultivated crops and may reach a height of 6 feet. Its large size and rapid production of rhizomes make this grassy weed immune to most cultural weed control methods. Professionally applied, selective herbicides are the best bet for removal.  


Scotts LawnService recommends cultural weed control practices to reduce Johnsongrass in your lawn and landscaping. This is due to the limited number of selective weed control product options to kill this weed. However, this weed can be controlled with non-selective weed controls such as Round-Up, which will kill this weed and surrounding turfgrass.  Re-seeding may be necessary to repair treated areas where Round-Up is used.

Scotts LawnService is the trusted industry leader for professional quality lawn care. Our exclusive lawn care products include premium grass seeds and professional-grade fertilizers; our lawn service teams consist of highly trained, industry-certified professionals. Contact a representative today for Johnsongrass control options available in your area and to learn how you can enjoy a lush, thicker lawn that only Scotts LawnService can deliver.