How To Get Rid Of Johnson Grass In Pasture

Johnson grass, also known as Sorghum halepense, is a common weed that can be difficult to control. It is a perennial grass that can grow up to 6 feet tall and has seed heads that resemble large corn tassels. Johnson grass is not only unsightly, but it can also be harmful to livestock and other plants. In this article, we will explore the different methods of controlling Johnson grass and how to prevent its growth.

What is Johnson grass?
Johnson grass is a perennial weed that is native to the Mediterranean region. It was introduced to North America in the early 19th century as a forage crop. Johnson grass has since become a common weed in fields, pastures, and roadsides. It is a perennial grass that can grow up to 6 feet tall and has seed heads that resemble large corn tassels.

Why is Johnson grass a problem?
Johnson grass is not only unsightly, but it can also be harmful to livestock and other plants. It is a tough, competitive weed that can crowd out other vegetation. Johnson grass is also high in nitrates, which can be toxic to animals if consumed in large quantities. Additionally, Johnson grass can reduce the quality and quantity of hay and forage.

How to identify Johnson grass?
The leaves of Johnson grass are long and narrow, with a prominent midrib and rough texture. The stems are hollow and can be up to 1 inch in diameter. The seed heads are large, fluffy, and resemble corn tassels. Johnson grass has a thick, fibrous root system that can be difficult to remove.

How does Johnson grass spread?
Johnson grass spreads through seeds and underground rhizomes. The seeds are commonly spread by birds, animals, and equipment. The rhizomes can grow up to 20 feet long and can sprout new plants wherever they come into contact with soil.

How to control Johnson grass?
Controlling Johnson grass can be challenging, but there are several methods that can be effective. These include chemical control, cultural control, and mechanical control.

Chemical Control
Chemical control involves the use of herbicides to kill Johnson grass. Glyphosate is a commonly used herbicide for Johnson grass control. It is a non-selective herbicide that will kill any plants it comes into contact with, so care should be taken to avoid desirable plants. Other herbicides that can be effective for Johnson grass control include imazapic, imazapyr, and fluazifop.

Cultural Control
Cultural control involves modifying the growing conditions to discourage Johnson grass growth. This can include maintaining proper soil fertility, planting desirable plants that will compete with Johnson grass, and mowing or grazing the area to suppress Johnson grass growth. Cultural control is often used in combination with other control methods.

Mechanical Control
Mechanical control involves physically removing Johnson grass from the area. This can include hand-pulling, hoeing, or cutting the plants. Mechanical control is most effective when combined with other control methods.

Preventing Johnson grass
Preventing Johnson grass from establishing is the most effective method of control. This can be done by keeping areas weed-free and avoiding planting contaminated seed or equipment. Prevention is key to avoiding the cost and effort of controlling an established Johnson grass population.


Q1. Is Johnson grass poisonous to humans?
Johnson grass is not poisonous to humans, but it can cause skin irritation. It is important to wear gloves and protective clothing when handling Johnson grass.

Q2. Can Johnson grass be used as forage?
While Johnson grass can be used as a forage crop, it is not recommended due to its high nitrate levels, which can be toxic to livestock.

Q3. How long does it take to control Johnson grass?
Controlling Johnson grass can take several years, depending on the method used and the extent of the infestation.

Q4. Can herbicides be harmful to the environment?
Herbicides can be harmful to the environment if not used properly. It is important to follow label directions and use herbicides only as directed.

Johnson grass can be a difficult weed to control, but it can be done with persistence and effort. Chemical, cultural, and mechanical control methods can be effective, but prevention is the key to avoiding established populations. By understanding the biology and growth habits of Johnson grass and implementing effective control methods, farmers and land managers can prevent the harm that Johnson grass can cause to livestock and other plants.