Weed Suppression

Cover crops can be a crucial part of a weed management program. When established in a timely manner, cover crops can compete with weeds for vital resources. Cover crops and cover crop residue can also create a physical barrier to prevent the establishment of weeds. Certain cover crops, like cereal rye, can release allelopathic chemicals that may hinder weed germination.

Importance of Biomass

Farmers looking to maximize weed suppression through cover crops must focus on management decisions to enhance cover crop growth and biomass.

Species Selection

It is essential to select cover crop species that establish quickly and produce high amounts of biomass. A quick and thorough establishment allows cover crops to outcompete weeds for resources and shade soils to decrease weed germination and growth.

Common Cover Crop Species for Weed Suppression


  • Winter Cereal Rye
  • Winter Triticale
  • Barley
  • Oats
  • Sorghum
  • Sudex (Sorghum-Sudangrass)
In a no-till system, cover crop residue left on the surface after termination will continue to provide a physical barrier to diminish weed germination and growth. Selecting species that produce high amounts of longer-lasting residue can enhance weed control during the following cash crop growing season.

Managing for Specific Weed Issues

NC State University Professor and Extension Weed Specialist Dr. Wesley Everman discusses management strategies to maximize weed suppression with cover crops like cereal rye. Management decisions like termination timing will depend on whether farmers are looking to target summer and winter annual weeds.

Cover Crops in a Weed Management Program

Cover crops may not eliminate the need for herbicides. However, they provide an additional weed control tactic for Integrated Weed Management. Adding other mechanisms for weed control can help mitigate issues with herbicide resistance.

References